Introduction 
The Computerized Delivery Sequence (CDS) File is a 5-digit ZIP Code based electronic customer product that 
provides and updates delivery sequence address information by carrier route for qualified mailers. Mailers must 
initially qualify for CDS information through Address Sequence Service, described in the Domestic Mail Manual 
(DMM) A920. 
The CDS File is a snapshot of the Address Management Services (AMS) database taken each Saturday (for 
weekly fulfillment) and on the second Saturday of each month (for bi-monthly fulfillment). The CDS product is 
distributed to customers bi-monthly on cartridge or CD/DVD, or weekly through electronic fulfillment. The first 
CDS product cycle of each year begins with the February product. The February product is created in January 
and is distributed to customers by the end of January at the latest. The subsequent bi-monthly products are 
April, June, August, October and December. Weekly electronic files will be available by close of business each 
Thursday, or on Friday when a holiday falls on Thursday. In the event of significant changes to ZIP Codes, a 
monthly supplemental CDS update may be distributed to bi-monthly CDS customers qualified in those ZIP 
Codes, at the discretion of the USPS. New CDS customers may begin receiving CDS fulfillment at anytime 
during the year. Upon qualification they will begin to receive fulfillment on the next bi-monthly cycle, or weekly 
fulfillment if the electronic option is chosen. 
All postal address products provide mailing address information and are not intended to provide physical location 
addresses. While the majority of the addresses found in United States Postal Service (USPS)address products 
are physical locations, not all physical locations will be found in USPS address products. 
This guide familiarizes potential customers with the CDS process, and includes: 
.. Qualification procedures 
.. Media format specifications 
.. Customer profile changes and transmission procedures 
.. File fee calculation and payment methods 
CDS customer benefits include access to walk sequence saturation discounts. 
For more information on CDS products, services, and technical support, call or send correspondence to: 
COMPUTERIZED DELIVERY SEQUENCE (CDS) DEPARTMENT 
NATIONAL CUSTOMER SUPPORT CENTER 
UNITED STATES POSTAL SERVICE 
6060 PRIMACY PKWY STE 201 
MEMPHIS TN 38188-0001 
800-238-3150 
Computerized Delivery Sequence (CDS) User Guide  July 2004 1 

Computerized Delivery Sequence (CDS) User Guide  July 2004 2 

Definitions of United States Postal Service (USPS) Terms 
Active Deliveries 
Active Deliveries do not include Vacants and PO Box Throwbacks. 
Address Management System 
The USPS address information database from which many address quality improvement products and services 
are derived. 
Carrier Possible Deliveries 
.. Delivery points which currently receive or have received delivery 
.. Delivery points on city routes to which carriers do not deliver because of alternate delivery PO Box or 
caller service (alternate delivery points are uniquely identified in the CDS base file) 
.. Delivery points on city routes vacant longer than 90 days and likely to be long-term vacancies, which 
are not considered seasonal (Long-term vacancy delivery points are uniquely identified in the base file) 
.. Delivery points delivered seasonally and are uniquely identified in the base file (it is the customers 
responsibility to determine the proper season for mailing) 
CDS File 
Electronic file containing a list of addresses or boxes from a box section, arranged in delivery sequence and 
served by a specific carrier. 
Note: If attempting to correct a CDS file, we do not recommend processing it through addressmatching 
software to correct it and then using the corrected file to prepare a walk-sequence 
mailing. 
CDS Subscription 
A one-year subscription to the CDS product that is renewable annually. Subscription fees must be received 
before renewed subscriptions will be fulfilled, and new subscriptions are prorated. The annual subscription period 
is February 1, through January 31 of the following year. 
Congressional District Number 
A standard value identifying a geographic area within the United States served by a member of the US House of 
Representatives or Senate. If Army/Air Force (APO) or fleet post office (FPO), this field will be blank. If there is 
only one member of Congress within a state, the code will be AL (at large). 
Customer Profile 
A specific CDS participant information summary record used internally by the USPS to identify customers and 
the ZIP Codes CDS customers are qualified to receive through the CDS fulfillment program. 
Delivery Point Code (DPC) 
A code consisting of the ZIP + 4, plus the last two digits of the primary address number for a street or firm 
address. DPCs for multi-delivery points are calculated using the secondary number. This code is used in the 
preparation of the mailer-applied, 11-digit delivery barcode and is included in every address record in the CDS 
file. 
Domestic Mail Manual (DMM) 
The Domestic Mail Manual (DMM) contains USPS regulations for domestic mail services. These regulations 
include: 
.. The rates and restrictions for postage 
.. Descriptions of the classes of mail and special services and conditions governing their use 
Computerized Delivery Sequence (CDS) User Guide July 2004 3 

.. Requirements for wrapping and mailing 
.. Explanations of collection and delivery services 
.. General provisions concerning the use of USPS services and facilities 
.. DMM A920 describes the Address List Sequence Services that comprise the CDS qualification process. 
Five-digit ZIP Code (5-digit ZIP Code) 
A numeric code that identifies areas within the United States and its territories and possessions to simplify 
USPS mail distribution. The five digits of the Zone Improvement Plan (ZIP) Code identify the individual post office 
delivery station associated with the address. This area is also called a zone. 
Post Office Box Possible Deliveries 
Box numbers within a box section that currently receive or have previously received delivery. 
Qualified Customer Electronic Address Lists 
To qualify for CDS, customer address lists must comply with the following applicable requirements for each 5digit 
ZIP Code area that the customer wishes to receive delivery sequence information: 
1. City Carrier Residence-Only Grouping  If the addresses are in a residence-only grouping, the list 
must contain at least 90 percent (but not to exceed 110 percent) of all possible residential city carrier 
deliveries within the 5-digit ZIP Code area. 
2. City Carrier Business-Only Grouping  If the addresses are in a business-only grouping, the list must 
contain at least 90 percent (but not to exceed 110 percent) of all possible business city carrier 
deliveries within the 5-digit ZIP Code area. 
3. City Carrier Combination Residence and Business Grouping  If the addresses are in a combined 
residence and business grouping, the list must contain at least 90 percent (but not to exceed 110 
percent) of all possible city carrier deliveries within the 5-digit ZIP Code area. 
4. Post Office Box Grouping  If the addresses (residential and business) are in a post office box grouping, 
the list must contain at least 90 percent (but not to exceed 110 percent) of all possible PO box deliveries 
within the 5-digit ZIP Code area. 
5. Rural and Highway Contract Route Grouping  If the addresses (residential and business) are in a rural 
or highway contract route grouping, the list must contain at least 90 percent (but not to exceed 110 
percent) of all possible Rural and Highway Contract deliveries within the 5-digit ZIP Code area. 
6. Combined Delivery-Type Grouping  If the addresses are in a grouping that combines more than one 
of the individual address groupings described in 1-5 above, the list must contain at least 90 percent 
(but not to exceed 110 percent) of all possible deliveries within each individual address grouping 
included in the list. 
ZIP + 4 Code 
A numeric code comprised of the 5-digit ZIP Code plus a 4-digit add-on assigned to an address. Every address 
has a ZIP + 4 code. 
Control of Lists Submitted for CDS File Updating 
Manager, Address Management Systems 
The Manager, Address Management Systems (AMS) manages the manual qualification procedures, updates all 
files within their district, and bills customers for manual address-sequencing services. 
Delivery Unit 
The local delivery unit (Post Office) verifies address cards or lists and performs manual card sequencing 
services to determine a customers eligibility to receive CDS updates. 
Computerized Delivery Sequence (CDS) User Guide July 2004 4 

National Customer Support Center (NCSC) 
The National Customer Support Center (NCSC) is the centralized site that generates CDS files for customers 
who have been qualified electronically at the NCSC or manually by the manager of AMS. The NCSC also 
manages the Electronic Address Sequence (EAS) Service qualification process. CDS processing and billing are 
performed at the NCSC in Memphis, Tennessee. The NCSC bills qualified CDS participants upon first-time 
qualification and throughout the year as appropriate. The NCSC also serves as the payment and customer 
support location for CDS customers. 
Control Record 
For each customer requesting CDS file information, the NCSC maintains a control record (customer profile) 
consisting of the following: 
.. Name and address of customer 
.. Name(s) and telephone number(s) of customer-authorized contact(s) 
.. List of 5-digit ZIP Codes and the date the appropriate delivery unit confirmed the customers manual 
qualification through the address card verification process 
.. Charges and payment information by 5-digit ZIP Code and customer name 
.. The customer is responsible for ensuring that the information in the customer profile is current. To 
change information in the profile, the customer must notify the NCSC in writing. Only the authorized 
contact(s) listed in the profile or a company officer may initiate a change to existing information. 
For assistance, write or call: 
COMPUTERIZED DELIVERY SEQUENCE (CDS) DEPARTMENT 
NATIONAL CUSTOMER SUPPORT CENTER 
UNITED STATES POSTAL SERVICE 
6060 PRIMACY PKWY STE 201 
MEMPHIS TN 38188-0001 
800-238-3150 
Transfer of CDS Subscription 
Qualified CDS customers who are current on all payments may transfer their CDS subscription to another party. 
Transfers are the reassignment of ZIP Codes from one CDS customer to another CDS customer. ZIP Codes are not 
retained by the original owner in a Transfer. Once a CDS subscription is transferred, the original customer becomes 
ineligible to receive the CDS data for ZIP Codes transferred unless they re-qualify. 
Transfer process: 
1. The CDS customer transferring ZIP Codes submits a Letter of Authorization to Transfer to the CDS Department. 
ZIP Codes being transferred must be listed in the letter or on an attached spreadsheet. Address 
groups for each ZIP Code must also be included. An electronic copy of the ZIP Code list, including address 
groups, should be provided if possible. The Letter of Authorization to Transfer must be on company letterhead 
and signed by the authorized CDS primary contact as listed in the CDS Customer Profile. 
2. Company name and contact information for the company receiving the transferred ZIP Codes must be included 
in the letter. 
3. The recipient company must be a current CDS customer or submit an application to become a CDS customer 
in order for ZIP Codes to be transferred. No transfer can occur until the application has been received 
and the recipient company has been assigned a CDS customer ID. Transfers will be completed once all 
information is received and verified. 
Cancellation of CDS Subscription 
CDS Subscriptions may be cancelled by written request only. Requests must be submitted on company 
letterhead and signed by the authorized CDS contact. Confirmation of cancellation will be provided upon 
completion. 
Computerized Delivery Sequence (CDS) User Guide July 2004 5 

Qualifying to Receive CDS File Information 
First-Time Qualification for Addresses Other Than Post Office Boxes 
1. The customer requesting CDS qualification must submit the Delivery Unit Summary (DUS) and 
address cards to the local AMS office, or an electronic address file and DUS to the NCSC. The 
Electronic Address Sequence Service (EAS) Users Guide can be found on the USPS RIBBS website 
at: http://ribbs.usps.gov/files/EAS/ 
2. Customers are notified they are qualified to receive CDS updates when they meet the qualification 
requirements as described in DMM Section A920. If the sequencing process shows the address files 
do not meet qualification requirements, the AMS Manager or the NCSC may suggest other address 
sequencing options. 
3. Current fees for address sequencing service are outlined in DMM Section R900.20. Fees for address 
sequence service are due regardless of qualification. 
The AMS Manager, or the NCSC, returns updated cards/files to the customer upon completion of the address 
sequence service process. It is the customers responsibility to provide payment for the address sequence 
service process within 30 days of the date of the invoice. Failure to do so will result in product suspension and 
requalification to be reinstated. 
First-Time Qualification for Post Office Box Addresses 
1. To qualify for CDS post office box addresses, customers must submit either address cards to the AMS 
Manager or an electronic file to the NCSC for address sequencing and correction service as stated in 
the DMM A920. It is permissible to submit addresses in a list format to the AMS Manager if you are 
requesting CDS qualification. 
2. If cards or an electronic address file is submitted, the process is the same as described for 
qualification in the previous section. 
3. If a list is submitted for CDS qualification only, the process is the same as the above 
section, with the following exceptions: 
.. The accuracy and completeness of the list is verified to determine whether it meets the 90-110 
percent requirement for CDS qualification 
.. No corrections are made to the list 
.. No fee is charged for verification of the list 
.. The verified list is not returned to the customer 
Qualifying Additional ZIP Code Areas 
Customers must qualify each additional ZIP Code area using the Address Sequence Service process described 
in the previous sections. 
Note: When the USPS creates a new ZIP Code area out of an existing one, customers may automatically 
qualify to receive updated information if they were qualified in the original ZIP Code area. 
Qualifying Additional Address Groupings in a Qualified ZIP Code 
When a customer is qualified to receive CDS information within a 5-digit ZIP Code area in a particular address 
grouping, and wants CDS information for additional address groupings, the customer must meet the requirement 
for each group as stated in DMM A920. Address groups include City Residential, City Business, City Residential 
and Business combined, PO Box, Rural/Highway Contract Routes or All (City Residential and Business combined, 
PO Box, Rural/Highway Contract Routes). Not all ZIP Codes contain all address groups. 
Customers qualified for the city residential address group in a ZIP Code may request the city business address 
group qualification if the number of city business possible deliveries is less than 10% of the total possible 
deliveries on city routes for the ZIP Code. Requests to add city business qualification to a ZIP Code must be 
made in writing to the CDS Department at the NCSC. 
Computerized Delivery Sequence (CDS) User Guide July 2004 6 

CDS Conversion Deferral 
Manual card customers can defer the beginning of an annual subscription to CDS for up to three months after 
qualifying. Deferred customer requests for CDS data must be submitted to the NCSC by the local AMS Manager. 
The request must include a copy of the complete 5-Digit DUS for the qualified ZIP Code. The request will 
be entered by the NCSC, and the CDS product will be fulfilled on the next monthly fulfillment. Upon receipt of the 
CDS data, the customer has 30 days to pay (see page 8, CDS File Fees). Failure to pay will result in product 
suspension, and qualification will be required to be reinstated. 
Seed Addresses 
In order to provide security for CDS list owners and to help prevent fraudulent use of rented or leased address 
files, a seed address process has been implemented. Each CDS customer who rents or leases their address 
file can be provided a seed address for each qualified ZIP Code and address group, if desired. Seed addresses 
should be included in customer address files only when the list is rented or leased. Seed addresses are unique 
to each customer and will be identified in the Address Sequence Service process. This prevents their address 
files from being qualified by someone else without permission. Seed addresses should be removed from the 
customers address file when sold to someone else. Seed addresses also should not be used if the customer 
does not rent or lease their files. 
The appropriate USPS District Address Management Systems office will be notified when a customer is unable 
to qualify due to the presence of a seed address. They will be responsible for notifying the delivery unit of the 
disqualification. The district or delivery unit as well as the NCSC will not accept the disqualified customers ZIP 
Code for subsequent processing for a period of one year. 
All requests for electronic DMM A920.4.0 processing will be posted on a password secured web site. The 
company name, contact name, mailing address, address groups requested and ZIP Code requested for sequencing 
will be listed. CDS customers will be a issued a password for access upon request. 
File Update Bi-monthly 
The annual CDS fee covers six bi-monthly updates and any additional updates that the AMS manager may 
specify due to changes in delivery sequence. Qualified customers will receive these supplemental updates when 
the USPS determines that an additional update is necessary. 
File Update Weekly 
The annual CDS fee covers one base file and 51 weekly updates. Weekly updates will be available for file 
transfer from a password protected site. Weekly updates will only contain data for routes where there have been 
changes to addresses. These changes may include sequence changes, changes to carrier route assignments, 
addition or deletion of addresses, etc. Weekly CDS subscribers will be expected to download and process their 
updates in sequence. Weekly files will be available for a period of four weeks before they are removed from the 
site. 
Note: The USPS strongly discourages skipping updates because they contain the most accurate 
walk sequence information available. To ensure that address files are as accurate and 
up-to-date as possible, customers should request and incorporate all included updates. 
Annual Update Requirement 
All qualified customers must reapply to maintain their CDS qualification. A CDS renewal form will be sent by the 
NCSC each November. The customer must update contact information, if applicable, sign and return the form to 
the NCSC CDS Department by December 31st. Failure to return the completed and signed renewal form will 
result in suspension of the CDS product and will require requalification to receive CDS data. CDS will not be 
renewed for customers with any outstanding invoices. 
Congressional District Code Files 
The Postal Service includes information on the Congressional District assignment of all addresses in order to 
provide statistics to Congress to be used when preparing their mailings. These Congressional district codes are 
linked to the ZIP + 4 code of every address. By referencing the ZIP + 4 codes associated with the addresses in 
Computerized Delivery Sequence (CDS) User Guide July 2004 7 

the CDS product, mailers can use the Congressional District Code Files to determine the Congressional district 
assigned to the addresses. This allows for targeting a particular Congressional district for a mailing list. Files will 
be provided monthly by file transfer from a password protected site, upon request. 
Security 
Changing Customer Profile Information 
1. Only the CDS Department at the NCSC can change customer profile information. 
2. Customers must provide written notification to the CDS Department to change profile information. Only 
authorized contacts who are listed in the existing customer profile record or a company officer may 
initiate a change to the Customer Profile. 
3. The CDS Department will confirm the authenticity of a request by calling the authorized contact listed 
in the existing profile record. 
Encryption 
All data files provided to customers are password encrypted. A USPS-supplied utility program allows customers 
to decrypt the file using the password. This utility program is currently available for Windows and UNIX/LINUX. 
Media Specifications 
CDS data is supplied to customers in the media format they request. A customer is permitted to select only one 
of the following formats in which to receive all CDS data: 
.. 3480 cartridge with ASCII character set and 38k BPI 
.. CD-ROM 
.. Electronic 
CDS File Fees 
Calculation 
Fees for CDS information are based on the number of possible deliveries per 5-digit ZIP Code provided to the 
customer. Call or write the NCSC Customer Support Department for the current schedule of fees. 
The fee is calculated per one thousand possible deliveries per 5-digit ZIP Code and prorated for increments less 
than a complete thousand. A minimum fee for one thousand possible deliveries is charged for ZIP Code areas 
with less than one thousand total possible deliveries. 
When payment is made annually, fees for CDS data are based on the number of deliveries that existed in the 
first release of CDS provided. When payment is made bimonthly, fees are based on the number of deliveries in 
each separate release. 
A minimum charge has been established for CDS subscriptions. Customers will be billed a minimum charge for 
subscriptions of 5000 or fewer addresses. 
Billing Options 
Customers may select Annual or Bi-monthly payment options. Annual billing is required for all CDS customers 
whose total annual bill is less than $200. Customer with annual totals of more than $200 who wish to pay the 
annual fee on a prorated bi-monthly basis must pay a premium of 5 percent per one thousand possible deliveries. 
Billing options may not be changed after January 1st. 
Payment 
CDS fees are based on an annual subscription. Customers will receive their invoice under separate cover from 
the CDS fulfillment product. No additional invoices or statements will be mailed to customers. 
Computerized Delivery Sequence (CDS) User Guide July 2004 8 

Important - Billing Options: Submit payment to the NCSC Customer Support Department via check, money 
order or credit card (Visa, MasterCard, American Express, Diners Club and Discover). Payment must be made 
in full for all CDS data provided. The NCSC will not accept payment for less than the full amount due. No refunds 
will be issued for subscriptions cancelled during the year. 
Customers who do not pay by the due date indicated on the CDS invoice are considered to be in default. Failure 
to make payment will result in disqualification for CDS and other USPS products and services. Once disqualified, 
requalification is required before a customer is eligible to receive future updates. All past due amounts 
must be paid in full before a customer may requalify. 
CDS File Formats 
CDS Volume Header Record 
FIELD FIELD 
RECORD POSITION POSITION 
FIELD DESCRIPTION LENGTH FROM T O 
RECORD TYPE INDICATOR 01 001 001 
MAILER ID 09 002 010 
FILE VERSION MONTH 02 011 012 
DASH 01 013 013 
FILE VERSION YEAR 02 014 015 
VOLUME SEQUENCE NUMBER 03 016 018 
ZIP COUNT 05 019 023 
ROUTE COUNT 07 024 030 
TOTAL RECORD COUNT 09 031 039 
FILLER 85 040 124 
Computerized Delivery Sequence (CDS) User Guide July 2004 9 

CDS ZIP Code Header Record 
FIELD FIELD FIELD 
REF FIELD RECORD POSITION POSITION 
NO. DESCRIPTION LENGTH FROM THRU 
1 RECORD TYPE INDICATOR 01 001 001 
2 FILE VERSION MONTH 02 002 003 
3 DASH 01 004 004 
4 FILE VERSION YEAR 02 005 006 
5 ZIP CODE 05 007 011 
6 ROUTE COUNT 05 012 016 
7 DELIVERY POINT RECORD COUNT 05 017 021 
8 RESIDENTIAL DELIVERY ACTIVE COUNT 05 022 026 
9 RESIDENTIAL DELIVERY POSSIBLE COUNT 05 027 031 
10 BUSINESS DELIVERY ACTIVE COUNT 05 032 036 
11 BUSINESS DELIVERY POSSIBLE COUNT 05 037 041 
12 PO BOX THROWBACK COUNT 04 042 045 
13 NO STAT COUNT 05 046 050 
14 SEASONAL COUNT 05 051 055 
15 VACANT COUNT 05 056 060 
16 DROP COUNT 05 061 065 
17 RESIDENCE BUSINESS SERVED 
DROP COUNT 05 066 070 
18 FILLER 54 071 124 
CDS Carrier Route 
FIELD FIELD FIELD 
REF FIELD RECORD POSITION POSITION 
NO. DESCRIPTION LENGTH FROM THRU 
1 RECORD TYPE INDICATOR 01 001 001 
2 ZIP CODE 05 002 006 
3 CARRIER ROUTE ID 04 007 010 
4 DELIVERY POINT RECORD COUNT 05 011 015 
5 RESIDENTIAL DELIVERY ACTIVE COUNT 05 016 020 
6 RESIDENTIAL DELIVERY POSSIBLE COUNT 05 021 025 
7 BUSINESS DELIVERY ACTIVE COUNT 05 026 030 
8 BUSINESS DELIVERY POSSIBLE COUNT 05 031 035 
9 PO BOX THROWBACK COUNT 03 036 038 
10 NO STAT COUNT 05 039 043 
11 SEASONAL COUNT 05 044 048 
12 VACANT COUNT 05 049 053 
13 DROP COUNT 05 054 058 
14 RESIDENCE BUSINESS SERVED 
DROP COUNT 05 059 063 
15 FILLER 61 064 124 
Computerized Delivery Sequence (CDS) User Guide July 2004 10 

CDS Delivery Point Record 
FIELD FIELD FIELD 
REF FIELD RECORD POSITION POSITION 
NO. DESCRIPTION LENGTH FROM THRU 
1 RECORD TYPE INDICATOR 01 001 001 
2 ZIP CODE 05 002 006 
3 CARRIER ROUTE ID 04 007 010 
4 DELIVERY SEQUENCE NUMBER 05 011 015 
5 RECORD TYPE CODE 01 016 016 
6 PO BOX THROWBACK INDICATOR 01 017 017 
7 DELIVERY ADDRESS NUMBER 10 018 027 
8 STREET PRE DIRECTION ABBREVIATION 02 028 029 
9 STREET NAME 28 030 057 
10 STREET SUFFIX ABBREVIATION 04 058 061 
11 STREET POST DIRECTION ABBREVIATION 02 062 063 
12 SECONDARY ADDRESS ABBREVIATION 04 064 067 
13 SECONDARY ADDRESS NUMBER 08 068 075 
14 DELIVERY TYPE CODE 01 076 076 
15 NO STAT COUNT 01 077 077 
16 DELIVERY POINT USAGE CODE 01 078 078 
17 DELIVERY POINT TYPE CODE 01 079 079 
18 ADDRESS VACANT INDICATOR 01 080 080 
19 DELIVERY POINT DROP INDICATOR 01 081 081 
20 RESIDENCE BUSINESS SERVED 
DROP COUNT 03 082 084 
21 SEASONAL DELIVERY INDICATOR 01 085 085 
22 PLUS4 - ZIP SECTOR CODE (2 bytes) 02 086 087 
PLUS4 - ZIP SEGMENT CODE (2 bytes) 02 088 089 
23 DELIVERY POINT DPBC DIGITS 02 090 091 
24 DELIVERY POINT DPBC CHECK DIGIT 01 092 092 
25 URBANIZATION LOCALE KEY 06 093 098 
26 PREFERRED LAST LINE LOCALE KEY 06 099 104 
27 FILLER 20 105 124 
CDS Congressional Code Record 
FIELD FIELD FIELD 
REF FIELD RECORD POSITION POSITION 
NO. DESCRIPTION LENGTH FROM THRU 
1 ZIP CODE 05 01 05 
2 PLUS4 - ZIP SECTOR CODE 02 06 07 
3 PLUS4 - ZIP SEGMENT CODE 02 08 09 
4 STATE 02 10 11 
5 CONGRESSIONAL DISTRICT 02 12 13 
Computerized Delivery Sequence (CDS) User Guide  July 2004 11 

Data Element Definitions 
Address Vacant Indicator 
A 1-byte field that specifies whether a delivery point has been unoccupied for 90 days or more: 
Y = Vacant 90 days or more 
N = Not vacant 
Business Delivery Active Count 
The total number of active business deliveries in the CDS ZIP Code Header Record. This field contains: 
.. The total number of active business deliveries for a given ZIP Code 
.. The total number of active business deliveries for a carrier route (in the CDS ZIP Route Header 
Record) 
Business Delivery Possible Count 
The number of possible deliveries in the CDS ZIP Code Header Record. 
.. The field contains the number of possible business deliveries for a given ZIP Code 
.. The number of possible business deliveries for a given carrier route (in the CDS ZIP Route Header 
Record) 
Carrier Route ID 
A 4-byte code assigned to a given mail delivery or collection route within a 5-digit ZIP Code area. The first 
character of this identification is alphabetic; the last three are numeric: 
Bnnn = PO Box 
Hnnn = Highway Contract 
Rnnn = Rural Route 
Cnnn = City Delivery 
Gnnn = General Delivery 
Delivery Address Number 
The numeric or alphanumeric component of an address preceding the street name  often referred to as the 
house number. Delivery address numbers that are preceded by significant leading zeroes are identified by a 
hyphen preceding the address number. All numeric data is right-aligned with leading zeroes, and all alphanumeric 
data is left-aligned. 
Delivery Point Barcode (DPBC) Digits 
The last two digits of the primary delivery address number (post office box number, rural route box number, or 
highway contract route number). Delivery point codes for multi-delivery points are calculated using the secondary 
number. 
Delivery Point Barcode (DPBC) Check Digit 
The last number in a barcode; it is calculated by the following formula: 
10  last digit of the sum of (ZIP5+ZIP4+DPBC). 
Example: If ZIP5 = 94497, ZIP4 = 9200, and DPBC = 00, 
then, 9+4+4+9+7+9+2+0+0+0+0 = 44 
10  4 = 6 
DPBC Check Digit = 6 
If the last digit of the sum of ZIP5 + ZIP4 + DPBC is 0 (zero), the check digit will be 0 (zero). 
Computerized Delivery Sequence (CDS) User Guide July 2004 12 

Delivery Point Business Family Served Count 
The number of potential deliveries for a drop site. If the Delivery Point Drop Indicator equals Y, the Business 
Family Served Count field contains the number of businesses or families served at that drop site. This number is 
greater than one (except for general delivery records, in which it can equal zero.) If the Delivery Point Drop 
Indicator equals N, the Business Family Served Count equals zero. If the Delivery Point Drop Indicator equals C, 
the Business Family Served count is greater than zero. 
Delivery Point Drop Indicator 
A 1-byte field that specifies whether a delivery point is a drop site. A drop is a single delivery point or receptacle 
that services multiple residences. Examples of drop sites include a single door slot shared by two residences, a 
box on a wall for duplexes, or a boarding house or fraternity in which mail is delivered to the door for subsequent 
distribution. Mail for drop sites is distributed internally by the site. 
A commercial mail receiving agency (CMRA) holds mail or forwards it to an addressee. Each CMRA must be 
registered with the post office responsible for delivery to the CMRA. They are also classified as drop sites 
because the carrier delivers the mail to one point from which the company distributes it to specific boxes. 
Y = Delivery point is a drop 
N = Delivery point is not a drop 
C = CMRA 
Delivery Point Record Count 
The total number of delivery points for a given area. In the CDS ZIP Code Header Record, this field contains the 
total number of delivery point records for a given ZIP Code; in the CDS Carrier Route Header Record, it contains 
the total number of delivery point records for a given carrier route. 
Delivery Point Type Code 
The physical type of delivery and related receptacle, such as curb boxes, CBUs or centralized (apartment-style) 
boxes. Other typically refers to single receptacles mounted on the building, such as a mailbox mounted by 
the front door of a house, or may refer to a business delivery where the carrier hands the mail to an employee or 
drops it in an In Box. 
Delivery Point Usage Code 
Indicates if the delivery is considered a residential or business delivery. 
A = Residential 
B = Business 
C = For future use 
D = For future use 
G = General 
Blank = None 
Delivery Sequence Number 
A numeric code indicating the position of an address within a carriers walk path. The order in which a carrier 
delivers mail can be determined by listing all address records for the carrier sorted by the delivery sequence 
number. 
Delivery Type Code 
A numeric sequence indicating the category of delivery point and its type of service: 
A Residential Curb A delivery point for a residence with a mail receptacle located at the curb. 
B Residential Cluster Box Unit (CBU) A delivery point consisting of residential cluster boxes. 
C Residential Central A delivery point within a building that has two or more ZIP+4 codes assigned to a 
bank of boxes (e.g., Arrow locks). 
D Residential Other A delivery point serviced other than by curb, central, or NDCBU. Examples of this 
delivery type include door-to-door (walking route) or door-slot delivery. 
Computerized Delivery Sequence (CDS) User Guide July 2004 13 

E Residential Facility Box  A residential customers PO box located in a USPS facility. 
F Residential Contract Box  A residential customers PO box located in a contract unit. 
G Residential Detached Box  A residential customers PO box that is not located in a post office building 
but for one which the USPS collects box rent. 
H Residential Non-Personnel Unit (NPU) A residential self-service postal center that furnishes essentialmail 
services such as collection and delivery of ordinary mail and sale of stamps. At a residential NPU, 
mail is delivered to mail boxes (similar to PO boxes). Residential NPU deliveries are non-staffed, selfservice 
and are most often found in rural areas. 
I Business Curb  A delivery point for a business with a mail receptacle located at the curb. 
J Business CBU  A delivery point consisting of business cluster boxes. 
K Business Central  A delivery point for a business serviced by receptacles that are within a delivery 
center or mailroom. 
L Business Other  A delivery point serviced other than by curb, central, or NDCBU. Examples of this 
delivery type include door-to-door (walking route) or door-slot delivery. 
M Business Facility Box  A businesss PO Box whose PO Box section is located at a USPS facility. 
N Business Contract Box  A businesss PO Box whose PO Box section is located at a USPS contract unit. 
O Business Detached Box  A businesss PO Box whose detached box section is not located in a post 
office building, but which is rented from the USPS. 
P Business Non-Personnel Unit  A self-service postal center that furnishes essential mail services, 
such as collection and delivery of ordinary mail and sale of stamps. At a business NPU, mail is delivered to 
mail boxes, similar to PO Boxes. Business NPUs are non-staffed, self-service units and are most often 
found in rural areas. 
Q General Delivery An alternate delivery service that allows customers with proper identification to pick up 
mail at post offices. Provided primarily at offices without letter carrier delivery or for transients and 
customers who do not have a permanent address or who prefer not to use PO Boxes. 
Drop Count 
The total number of drop sites. In the CDS ZIP Code Header Record, this field contains the total number of 
drop sites for a given ZIP Code; in the CDS ZIP Route Header Record, it contains the total number of drop 
sites for a given carrier route. It is NOT the number of customers served by those drop sites. The number of 
customers served by these drops can be found in the Resident/Business Served Drop counts. 
File Version Month 
The month for this edition of the file. 
File Version Year 
The last two digits of the year for this edition of the file. 
Mailer ID 
The CDS customer ID number. 
No Stat Code 
An indicator flag at the delivery point level that can be set in AMS to indicate no delivery and that the address is 
not to be counted as a possible delivery. Addresses where delivery has not been established or are long term 
vacancies are coded as No Stats. 
No Stat Count 
The total number of delivery points coded as a No Stat record. 
Plus4(+4) 
A 4-digit sequence consisting of the sector and segment numbers. The +4 further subdivides the ZIP Code area. 
Computerized Delivery Sequence (CDS) User Guide  July 2004 14 

PO Box Throwback Count 
The total number of PO throwbacks for an area. In the CDS ZIP Route Header Record, the PO Throwback field 
contains: 
.. The total number of PO throwbacks for a given carrier route 
.. The total number of PO throwbacks for a given ZIP Code (in the CDS ZIP Code Header Record) 
PO Box Throwback Indicator 
The address of this delivery point is a street address, but actual delivery is made to the customers PO box 
address. 
T = PO Box Throwback 
Preferred Last Line Locale Key 
This field contains the locale key of the preferred last line of a particular delivery point and is used to locate that 
delivery points preferred city name in City State Product. 
Record Type Code 
An alphabetic value that identifies the type of data in the record. 
F = Firm 
G = General 
H = Highrise 
P = PO Box 
R = Rural Route 
S = Street 
Record Type Indicator 
A 1-byte field that identifies the type of CDS record. 
1 = Volume Header Record 
2 = ZIP Code Header Record 
3 = ZIP Route Header Record 
4 = Detail Record 
Residence Business Served Drops Count 
The total number of families or businesses served by a drop delivery or other multi-service delivery point for a 
given area. In the CDS ZIP Route Header Record, this field contains the number of families or businesses 
served by a drop delivery or other multi-service delivery point for a given carrier route; in the CDS ZIP Code 
Header Record, it contains the number of families or businesses served by a drop delivery or other multiservice 
delivery point for a given ZIP Code. 
Residential Delivery Active Count 
The total number for active residential deliveries for a given area. In the CDS ZIP Route header Record, this 
field contains the number of active residential deliveries for a given carrier route; in the CDS ZIP Code Header 
Record, it contains the number of active residential deliveries for a given ZIP Code. 
Residential Delivery Possible Count 
The total number of possible residential deliveries for a given area. In the CDS ZIP Route Header Record, this 
field contains the number of possible residential deliveries for a given carrier route; in the CDS ZIP Code 
Header Record, it contains the number of possible residential deliveries for a given ZIP Code. 
Route Count 
The total number of routes for a given area. For the CDS ZIP Header Record, this field gives the number of routes 
for a given ZIP Code; in the CDS Volume Header Record, it contains the number of routes for a given volume. 
Computerized Delivery Sequence (CDS) User Guide July 2004 15 

Seasonal Delivery Indicator 
A 1-byte field that specifies whether a given address receives mail only during a specific season (e.g., a summer-
only residence). 
Y = Delivery point has seasonal delivery 
N = Not applicable 
E = Educational Delivery (school, dormitory, student housing) 
Seasonal Count 
The total number of seasonal deliveries for a given area. In the CDS ZIP Code Header Record, this field gives the 
number of seasonal deliveries for a given ZIP Code; in the CDS ZIP Route Header Record, it contains the number 
of seasonal deliveries for a given carrier route. 
Secondary Address Abbreviation 
A descriptive code that identifies the type of secondary address range. 
Value Description Value Description 
APT Apartment 
BLDG Building 
BSMT* Basement 
DEPT Department 
FL Floor 
FRNT* Front 
HNGR Hangar 
LBBY* Lobby 
LOT Lot 
LOWR* Lower 
OFC* Office 
PH* Penthouse 
PIER Pier 
REAR Rear 
RM Room 
SIDE* Side 
SLIP Slip 
SPC Space 
STE Suite 
STOP Stop 
TRLR Trailer 
UNIT Unit 
UPPR* Upper 
KEY Key 
*When these abbreviations are used, a 
secondary address number is not required. 
See the latest version of Publication 28, 
Postal Addressing Standards, for a complete 
list of secondary address abbreviations. 
If any discrepancies exist between 
this document and Publication 28, the most 
current version of Publication 28 always 
takes precedence. 
Secondary Address Number 
The alpha and/or numeric sequence that specifically identifies a unit at an address. The number may represent 
an apartment, room, suite, floor, space, or other similar addressable unit. Apartment or room numbers that are 
preceded by significant leading zeroes are identified by a hyphen preceding the number. All numeric data is 
right-aligned with leading zeroes, and all alphanumeric data is left-aligned. 
Street Name 
The official name assigned to a street by a local governing authority. This field contains only the street name and 
does not include directional or suffix components. This element may also contain literals (e.g., PO Box, General 
Delivery, USS, PSC, or UNIT). 
Numeric street names that have numeric components of four characters (or less) are aligned so the low-order 
digit of the number is in the fourth position of the field. This shift is made so that the numeric street names 
appear in numeric sequence. 
Street Post-Direction Abbreviation 
A geographical direction following a street name. 
E East 
N North 
NE Northeast 
NW Northwest 
S South 
SE Southeast 
SW Southwest 
W West 
Computerized Delivery Sequence (CDS) User Guide July 2004 16 

Street Pre-Direction Abbreviation 
A geographic direction preceding a street name. 
Spaces No Pre-Direction 
E East 
N North 
NE Northeast 
NW Northwest 
S South 
SE Southeast 
SW Southwest 
W West 
Street Suffix Abbreviation 
A standard USPS code for a word frequently appearing as a trailing designator in street addresses. See the 
latest version of Publication 28, Postal Addressing Standards, for a complete list of street suffix abbreviations. 
If any discrepancies exist between this document and Publication 28, the most current version of Publication 28 
always takes precedence. 
Examples of Street Suffix Abbreviations are listed on page 18. 
Computerized Delivery Sequence (CDS) User Guide July 2004 

Examples S treet Suffix Abbreviation s 
ALY Alley ANX Annex 
ARC Arcade AVE Avenue 
BYU Bayou BCH Beach 
BRK Brook BG Burg 
BYP Bypass CP Camp 
CYN Canyon CPE Cape 
CSWY Causeway CTR Center 
CIR Circle CLFS Cliffs 
CLB Club COR Corner 
CORS Corners CRSE Course 
CT Court CTS Courts 
CV Cove CRK Creek 
CRES Crescent XING Crossing 
DL Dale DM Dam 
DV Divide DR Drive 
EST Estates EXPY Expressway 
EXT Extension FALL Fall 
FLS Falls FRY Ferry 
FLD Field FLDS Fields 
FLT Flats FRD Ford 
FRST Forest PATH Path 
PIKE Pike PNES Pines 
PL Place PLN Plain 
PLNS Plains PLZ Plaza 
PT Point PRT Port 
PR Prairie RADL Radial 
RNCH Ranch RPDS Rapids 
RST Rest RDG Ridge 
RIV River RD Road 
ROW Row RUN Run 
SHL Shoal SHLS Shoals 
SHR Shore SHRS Shores 
SPG Spring SPGS Springs 
SPUR Spur SQ Square 
STA Station STA Stravenue 
STRM Stream ST Street 
SMT Summit TER Terrace 
TRCE Trace TRAK Track 
TRL Trail TRLR Trailer 
TUNL Tunnel TPKE Turnpike 
UN Union VLY Valley 
VIA Viaduct VW View 
VLG Village VL Ville 
VIS Vista WALK Walk 
WAY Way WLS Wells 
Computerized Delivery Sequence (CDS) User Guide  July 2004 

Total Record Count 
The total number of delivery point records for a given area. 
Urbanization Locale Key 
The locale key of an urbanization for a given delivery point; it is used only with addresses in Puerto Rico. This 
field is used to locate the urbanization name in City State Product. 
Vacant Code 
A code that identifies a delivery point unoccupied for over 90 days. 
Vacant Count 
The total number of delivery points unoccupied for over 90 days for a given carrier route. 
Volume Sequence Number 
A number representing the position of any given volume within the entire set of tapes/cartridges. 
ZIP Code 
ZIP is an acronym for Zone Improvement Plan. It is a 5-digit code that identifies a specific geographic delivery 
area. ZIP Codes can represent an area within a state, an area that crosses state boundaries (unusual condition) 
or a single building or company that has a high mail volume. 
ZIP Count 
The total number of ZIP Codes for a given volume. 
ZIP Sector Code 
The first two digits of the 4-digit ZIP add-on code. This code represents a smaller geographic area within a ZIP 
Code area. ZIP sector boundaries are established so as not to cross state or county lines. 
ZIP Segment Code 
The last two digits of the 4-digit ZIP add-on code, which represent a smaller geographic area within a ZIP 
Sector area. Geographically, ZIP segments represent areas such as one side of a city block between intersections; 
both sides of a street, including cul-de-sacs; a company or building; a floor or group of floors within a 
building; a cluster of mailboxes; sections of post office boxes; or other similar delivery groups. 
Computerized Delivery Sequence (CDS) User Guide  July 2004