Anonymous interactive telephone system

A method and apparatus for establishing telephone communications between service subscribers and responding callers through a central system while preserving confidentiality and mutual anonymity of the subscribers and callers. Incoming calls from callers intended for subscribers identified by coded entries, are transferred by the system controller and a digital switch either to a message recording facility or directly to the subscriber. If the subscriber is unavailable, a message can be left by the caller, but does not need to include the telephone number of the caller. The subscriber then is able to call the caller, through the central system controller, without breaching anonymity of either the caller or the subscriber.

BACKGROUND OF THE INVENTION 
The present invention relates to a method and a system for placing and 
responding to published advertisements. 
Many magazines and newspapers regularly publish special classified sections 
commonly referred to as "personals" in which parties wishing to form 
relationships with other parties may place ads. The typical ad describes 
the person placing the ad, the type of relationship desired, and the type 
of person he or she would like to meet. Other persons reading such ads and 
also wishing to form personal relationships, will contact the person who 
placed the ad if their interest appear to coincide. Contact is established 
between such persons by mail, generally sent to a blind post office box 
keyed to a code appearing in the ad. The post office box is usually 
managed by the magazine or newspaper. 
Some people hesitate to use the "personals", even though they are 
interested in establishing relations, because of a perceived indignity in 
the process. Others feel uncomfortable about revealing personal 
information to a stranger. And there are some who will not respond to a 
"personals" ad because they feel that they are unable to communicate 
effectively in writing. Finally, for all those who use the "personals", 
there is no way of eliminating a delay of a few days or more between the 
appearance of an ad and the contact between two interested parties. 
There is therefore a need to favorably alter the perception about 
individuals who use "personals" and thereby increase the number of people 
placing and responding to such ads. 
There also is a need to provide a "personals" service in which 
confidentiality and anonymity of all parties can be preserved. 
Further, there is a need for a "personals" service in which responding to 
an ad can be accomplished without using the mailed letter format. 
Additionally, there is a need for a "personals" service which enables an 
immediate and direct contact between a person answering an ad and the 
person who placed the ad. 
There is also a need for an advertising system that can be easily modified 
in its format, and done so by the subscriber to the system. 
Finally, there is a need to expand certain of these concepts to standard 
classified advertisement systems. 
Objects of the present invention are to satisfy each of these needs. 
SUMMARY OF THE INVENTION 
This invention relates to a telephone system through which mutually 
anonymous parties may conduct telephone communication with each other, 
without delay, and maintain such communication anonymous for as long as 
they desire. 
In accordance with the present invention, "personals" ads are placed and 
published as previously known. A person reading an ad (hereinafter 
referred to as the caller), and interested in establishing a personal 
relationship with the person who placed the ad (herein referred to as the 
subscriber), uses his or her telephone and calls a telephone number 
published in the "personals" column. The number called connects the caller 
to a central computer-based system, and the caller is prompted (by speech 
synthesis, recorded message, or the like) to enter the subscriber's 
reference number (SRN) furnished in the ad and unique to the subscriber. 
The computer then uses the subscriber reference number as an index to 
locate the subscriber's telephone number, and after verifying certain 
conditions to be explained below, automatically connects the caller to the 
subscriber. Only the computer is aware of the identity of the subscriber 
and the subscriber's telephone number (and the caller as well), and hence 
the parties can communicate with one another while being mutually 
anonymous for as long as they desire. 
If the subscriber to whom a call is placed is not available or does not 
wish to answer the telephone, or if the subscriber's line is busy, the 
system offers the caller the ability to record a personal voice message 
for the subscriber. The caller is not, however, required to reveal his or 
her identity or telephone number to the subscriber in order to enable the 
subscriber to call back. Such feature of the system is achieved by the 
computer assigning to the caller a unique callback reference number (CBRN) 
that is indexed by the computer to the caller's phone number. The callback 
reference number is automatically included with any voice message that was 
left by the caller. The subscriber then may return the call from the 
caller by using the caller's callback reference number, and speak with the 
caller while maintaining complete privacy for both parties. 
The preservation of such mutual anonymity, and the capability of rapidly 
exchanging personal thoughts and feelings over the telephone, involves a 
completely new concept for establishing relations between individuals 
through the "personals". 
The specifics of the present invention which make possible such new 
concept, together with the objects and advantages noted above, will become 
apparent when reference is made to the accompanying drawings and the 
following description.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now to the drawings in detail, and with particular reference 
first to FIG. 1, the anonymous interactive telephone system of the present 
invention is generally referred to by reference number 10. The interactive 
telephone system 10 involves the interlinking through the public telephone 
service switching network, shown generally at 13 of a subscriber to the 
"personals" service and an interested party (the caller). The subscriber 
has a telephone at a subscriber station 14, and the caller has a telephone 
at a caller station 16. The parties located at the respective stations 14 
and 16 are mutually anonymous, but both are aware of the telephone number 
of the "personals" service through which communication with complete 
confidentiality is assured, all of which will be explained in detail 
hereinafter. 
Through public telephone line 11a and the known public telephone service 
switching network 13, a caller at station 16 can reach an incoming trunk 
line of the system 10 at caller port A, via public telephone line 12a. 
This is accomplished by calling a telephone number published in the 
"personals" column. Similarly, the subscriber at station 14, via public 
telephone line 11b and switching network 13, can reach an incoming trunk 
line of the system 10 at subscriber port B, via public telephone line 12b, 
identified preferably by a second telephone number known only to 
subscribers to the "personals" service. 
In general, lines 11a and 11b, switching network 13, and lines 12a and 12b 
are provided by the public telephone service. In this regard, all services 
and equipment provided by the public telephone service are included within 
the box outlined by dotted line 17. 
Ports A and B connect to a digital switch 18, the switching at which is 
controlled by a system controller 20. While not illustrated, ports A and 
B, as well as other components to be described hereinafter, are connected 
to switch 18 through many lines; similarly, switch 18 and other components 
to be described hereinafter, are connected to controller 20 through many 
lines, although only one is illustrated for clarity. Further, although not 
illustrated, numerous known connecting components, such as modems for 
example, form part of the system 10. 
A port C interlinks the digital switch 18 to a speech prompting and 
recording system 32, while an outgoing port D, designated by the number 
34, is connected to public telephone lines 12c and 12d capable of 
connecting together the caller station and the subscriber station, via 
public telephone service switching network 13 and telephone lines 11a and 
11b. Next, a billing terminal 36 is connected to the system controller 20; 
and finally, a credit verification port E interlinks the system controller 
20 with a credit verification/authorization facility 38. 
The different operational steps and component connections referred to 
hereinbefore and further described hereinafter are under the control of 
the digital switch 18 which receives commands from the controller 20, or 
in some cases are under the control of the controller 20 directly. System 
controller 20 can take the form of known general purpose computers, and 
includes memory 20a and memory index 20b discussed hereinafter. Thus, 
programmed operation of the system controller 20 will provide the 
appropriate commands to the digital switch 18 and other system components 
for effecting the different operational modes in accordance with the 
present invention. 
The mutually anonymous parties at the subscriber and caller stations 14 and 
16, interact with the system 10 of the present invention by presently 
available touch-tone telephone equipment in accordance with one embodiment 
of the invention. However, the present invention contemplates the use of 
speech recognition and other advanced forms of user inputs through which 
callers and subscribers may interact with the system. 
The primary service provided by the system of the present invention 
involves connecting together, over the telephone lines, a party at a 
subscriber station 14 and a caller at a caller station 16 for the purpose 
of their establishing a confidential and anonymous communication with one 
another; such communications can be initiated by either party. In 
operation, a subscriber places an advertisement with a magazine, 
newspaper, or other media offering a "personals" service and provides to 
the service the wording for a "personals" ad, as well as appropriate 
instructions relative to his or her desires about receiving calls, such as 
time-of-day, day-of-week availability, etc., and appropriate billing 
information. The subscriber also provides his or her telephone number. 
The "personals" service then stores the subscriber-provided information in 
the memory unit 20a of system control 20, takes steps to publish the ad, 
and indexes the subscriber's telephone number in the memory 20a, via 
memory index unit 20b, of the system controller 20 to a unique subscriber 
reference number (SRN) to be published in the ad. The "personals" ad then 
is published, and it is read by potentially interested parties. Also 
published is a telephone number that will connect a caller to the system 
10 through caller port A, and details about the use of the anonymous 
interactive telephone system. 
A caller initiates a telephone contact with the system 10 by calling the 
telephone number published in the "personals" column. The telephone is 
answered by the speech prompting component of system 32 through a digital 
switch 18 under the control of system controller 20. The caller is 
prompted to enter credit card information and then a subscriber reference 
number by touch-tone input from his or her telephone. In response to entry 
of an SRN, the system controller 20 opens the file of the appropriate 
subscriber and reads the stored instructions from memory 20a. The speech 
prompting component of system 32 then furnishes information through the 
telephone connection to the caller, based on stored instructions from the 
subscriber. The incoming call from the caller then is transferred either 
to the subscriber station 14 through the outward dialing port 34, or to 
the speech recording component within system 32. 
If the call is made at a time acceptable to the subscriber, the system 
controller 20 instructs switch 18 and outward dialing port 34 to call the 
subscriber station 14 at the stored telephone number. Once the telephone 
connection is established, the speech prompting component of system 32 
preferably requests verification from the subscriber before connecting the 
caller to the subscriber; such verification could be accomplished by 
touch-tone of the subscriber's personal access code () or, 
alternatively, the subscriber's telephone number. Once it is verified that 
an authorized individual is on the telephone at the subscriber station 14, 
connection of the caller to the subscriber is permitted. At no time will 
either party know the identity or telephone number of the other party 
unless volunteered during the telephone conversation. 
Upon completion of the call, the length of the call is sent to the system 
controller 20 and subsequently is transmitted to the billing terminal 36; 
the caller then is billed for the call on the basis of credit information 
previously obtained by the speech prompting component of system 32, 
provided by the caller through his or her touch-tone telephone, verified 
by credit facility 38, and stored in the memory 20a of system controller 
20. 
If the incoming telephone call from the caller station 16 to the subscriber 
station 14 cannot be completed (line busy, no answer, wrong time or day, 
etc.), the call is directed to the speech recording section of system 32. 
In such case, the caller is asked whether he or she desires that the 
subscriber return the call, and if so, is requested by the speech 
prompting component of system 32 to furnish his or her telephone number, 
to be available only to the system controller. The caller then enters his 
or her telephone number, by way of the caller's telephone touch-tone pad, 
which is indexed to the requested subscriber and stored in the database 
memory 20a of controller 20. The caller at that time is assigned a unique 
callback reference number (CBRN) that is announced to the caller by the 
speech prompting system. As the next step, the caller is asked by the 
speech prompting system whether he or she wishes to furnish a voice 
message to the subscriber. Such a recorded voice message, if left, is 
stored in the speech recording component of system 32 for subsequent 
review by the subscriber to whom the message is addressed. 
The subscriber may call into the system 10 at any time in order to review 
messages (or to perform other tasks described hereinafter). The initial 
contact is made with the speech prompting component of system 32, as 
hereinbefore described with respect to incoming calls from the caller, 
when the subscriber calls the telephone number of subscriber port B. The 
speech prompting component of system 32, under the direction of the system 
controller 20, asks the subscriber for his or her subscriber reference 
number, and then looks up the SRN in the system controller memory 20a. 
Once the SRN is verified, recorded data and messages directed to that 
particular subscriber may be reviewed by the subscriber. The subscriber 
may then, for example, enter instructions to the system controller 20 
regarding, for example, which calls, if any, are to be returned. The 
subscriber may return a telephone call from a caller by touch-tone entry 
of the caller's callback reference number furnished to the subscriber by 
the system controller 20 through the speech prompting component of system 
32. Once again, connection is made between the caller and the subscriber 
without either party knowing the identity or telephone number of the 
other. 
With reference now to FIG. 2, it will be explained how the system 
controller 20 is programmed to control operation of the digital switch 18 
and the various components relating to speech prompting and recording, 
billing, and call transferring, for interfacing a caller station 16 with 
the system 10. The program is initiated by the caller as indicated at 40 
in FIG. 2. When the telephone number of caller port A is called, 
connection is initiated at 50. The speech prompting component of system 
32, under control of the system controller 20 and the digital switch 18, 
transmits a greeting to the caller as indicated at 52, and requests 
certain data in order to initiate a data verification procedure 54. 
As shown in greater detail in FIG. 2A, the data verification procedure in 
accordance with one embodiment of the invention involves receiving credit 
card data in response to a request, and then searching of a remote 
database (credit verification/authorization facility 38 of FIG. 1) for 
verification of the credit card number. Such data verification procedure 
is further detailed in FIG. 3, and is initiated by a request 60 for data 
followed by the caller's entry at 62 of the requested data. The caller 
then verifies at 64 that the data was correctly received, resulting in a 
decision 66 that the entered data should be utilized. If the entered data 
is not verified, the procedure is repeated a predetermined number of 
times, such as 3, until verification occurs. If the entered data is not 
verified, then the incoming call is disconnected. The process continues to 
the next sequence if verification occurs. 
With continued reference to FIG. 2A, following verification of the of 
credit card type at 58, the credit card number is verified as indicated at 
68. Then, the expiration date of the credit card is verified as indicated 
at 70. The verification procedure is completed by an update operation 72 
of the database forming a part of system controller 20. 
After credit verification, the system requests the subscriber reference 
number from the caller. The SRN is touch-tone entered by the caller and 
such entry is verified as indicated at 74 in FIG. 2B. The verification 
procedure 74 is similar to that described in FIG. 3 as hereinbefore 
described. 
After SRN verification, the system issues a command at 76 (FIG. 2B) to 
access the subscriber instruction file 78. In accordance with one 
embodiment of the invention, the subscriber instruction file contains 
various parameters such as status, activity time, and caller message 
duration. Under the status parameter, the subscriber may instruct the 
system, through a subscriber interfacing program hereinafter described, 
that the subscriber reference number is to be deactivated or activated. If 
deactivated, the system will not transfer calls or take messages, but will 
deliver to the caller an appropriate informational message by the speech 
prompting system. 
If the subscriber reference number is active, the system will transfer 
telephone calls from callers in accordance with the activity time and 
message duration parameters. In regard to the activity time parameter, the 
subscriber may furnish to the system the desired days of the week and the 
active hours during each day that calls will be accepted. With respect to 
receipt of caller messages, the message duration parameter will limit the 
duration of verbal messages within specified limits in order to 
accommodate limited time for message review. Information on the foregoing 
parameters of the subscriber instruction file 78 may be furnished to the 
caller by the speech prompting component of system 32 as a courtesy along 
with general information about the system. The caller is also advised by 
the system that it is checking to see if the requested subscriber is 
currently available. Such program checking step is depicted at 80. As 
indicated by reference number 82, if the subscriber is available, a call 
transferring operation is initiated as depicted at 84. If the subscriber 
is not available, then the incoming call from the caller is transferred to 
a recorder under a speech recording operational mode 86, and the telephone 
number of the caller is requested at 87 for a message to the subscriber. 
FIG. 4 illustrates in greater detail the program associated with the call 
transferring operation, initiated by a search of the database at 88 for 
the subscriber's telephone number corresponding to the SRN entered by the 
caller. An outgoing trunkline through outward dialing port 34 is then 
obtained at 92. Such trunkline is connected to the desired subscriber 
station 14 as shown at 94, utilizing the subscriber telephone number 
retrieved from the database. If the subscriber's line is busy, as 
indicated by the program decision 96, the outgoing transferred call to the 
subscriber is terminated as indicated at 98. Or if the timeout period 
expires without the subscriber answering the telephone, a line disconnect 
decision at 100 occurs, and the call attempt is terminated. Otherwise, a 
telephone connection to the subscriber is completed when the subscriber 
answers the telephone. The answering subscriber then is prompted to enter 
his or her personal access code, telephone number, or subscriber reference 
number, by touch-tone input, and the SRN is verified at 106. During the 
time when the subscriber is being called and the SRN is being verified, 
the speech prompting component of system 32 communicates with the caller 
to provide updates on the status of the call. Once the connection between 
the caller and the subscriber is established, the system removes the 
speech prompting component of system 32 from the connection. 
Referring again to FIG. 2B, it will be noted that following establishment 
of the telephone connection between the caller and the subscriber, the 
program continues by waiting for completion of the call as indicated by 
reference number 188. A charge computation step 190 then ensues, followed 
by a connection closing operation 192. A database update operation 194 
completes the caller interfacing program. 
In the event the subscriber to whom a call is to be transferred is not 
available, then a message recording mode ensues as indicated by reference 
number 86 in FIG. 2B. Following such message recording operation, the 
caller may select another subscriber as indicated by reference number 196. 
In such case, another interfacing program is initiated, bypassing the data 
verification portion thereof. In the event that no other call is to be 
initiated, as indicated by decision 196, then the program proceeds to a 
disconnect operation at 198 followed by the charge computation, connection 
closing, and database update steps 190, 192, and 194 before the caller 
interfacing program is completed. 
Referring now to FIG. 5, illustrating the program for the message recording 
mode of operation, such operational mode is initiated with an announcement 
from the speech prompting component of system 32 to the caller that the 
subscriber is unavailable and a message can be left as indicated by 
reference number 200. If no message is desired, the program terminates and 
the call is disconnected as hereinbefore described with respect to FIG. 
2B. On the other hand, if the caller wishes to leave a message, as 
indicated at decision 202, the caller telephone number is requested and 
then verified by a verification operation as indicated by reference number 
204. A callback reference number is assigned as indicated at 206 and is 
indexed to the caller's telephone number. Additionally, the caller 
information is indexed to the particular subscriber to whom the call was 
placed. The assigned callback reference number is announced to the caller 
as indicated at 208, followed by the furnishing of voice message recording 
instructions as indicated at 210. A recording and playback operation 212 
then ensues. The caller is then given the option, as indicated at 214, of 
either accepting or rejecting the recorded message. If the recorded 
message is rejected, another record/playback session occurs. Once the 
caller hangs up at the end of a record/playback session, the message 
recording mode is terminated and the database is updated as indicated at 
216. 
FIG. 6 illustrates the subscriber interfacing program initiated by an 
incoming call to the system 10 from a subscriber station 14 through the 
subscriber port B, under control of the digital switch 18 and the system 
controller 20. Such incoming call of the subscriber is met by a greeting 
originating from the speech prompting component of system 32 similar to 
the incoming call program illustrated in FIG. 2 with respect to the caller 
station 14. The subscriber is then prompted to enter by touch-tone input, 
an access code which is either the same as the published subscriber 
reference number, or if more security is desired, an unpublished code 
given to the subscriber when initiating the service. The access code is 
then verified by a verification operation 218. 
Upon verification of the access code of the subscriber, the subscriber may 
make a selection from a variety of services pursuant to a service 
selection program 220. In accordance with the embodiment illustrated in 
FIG. 6, the menu of services includes a custom message service 222, a 
contact caller service 224, a message review service 226, an instruction 
entry service 228 and a message statistic service 230. After the selected 
services are performed, the program continues as indicated at 232 to a 
disconnect operation 234 followed by a charge computing step 236 and a 
system administration step 238. The system is then reset to receive 
another incoming call from the subscriber. 
The service selection program 220 hereinbefore referred to in connection 
with FIG. 6, is illustrated in greater detail in FIG. 7. The selection 
program is initiated by speech prompting information transmitted at 240 to 
the subscriber for entering his or her code selection instructions. The 
subscriber then enters a selection code number as indicated at 242 in 
order to initiate a selection execution program 244. The selection 
execution program 244 consists of a plurality of decision steps 246.sub.1 
-246.sub.n, the number of code decision steps in the illustrated 
embodiment being five as depicted in FIG. 6. 
The program associated with the message statistic service 230 is 
illustrated in detail in FIG. 8. Such program is initiated by an operation 
providing access to the system database as indicated by reference number 
248 followed by an announcement to the subscriber of the message statistic 
data, as indicated at 250, followed by the step 252 wherein the 
subscriber, through speech prompting instructions and touch-tone answers, 
controls the review of such data. The procedure is optionally repeated as 
indicated at 254 before the message statistic program is terminated. 
FIG. 9 illustrates in detail the custom message program 222. This program 
is initiated by a speech prompting message to the calling subscriber 
inquiring as to message selection, as indicated by reference number 256. 
The subscriber then enters a selection code as indicated at 258 which is 
followed by an announcement at 260 of the selection made. If a correct 
code selection is indicated as denoted by reference number 262, the 
program is terminated by an update database operation 264. 
Subroutine 224 for a subscriber to return the call of a caller is 
illustrated in greater detail in FIG. 10. This program is initiated by a 
speech prompting announcement to the subscriber providing instructions for 
entry of information as indicated by reference number 266. The subscriber 
then enters a desired callback reference number as indicated at 268 which 
step is followed by a database check 270. If the callback reference number 
entered by the subscriber is valid, as indicated at 272, the telephone 
call from the subscriber is directed to the desired caller station in 
accordance with a confidential communication program 56' hereinbefore 
described. Upon completion of the call between the subscriber and the 
caller, the call is terminated; or if the subscriber remains on the line, 
he or she may select another caller as indicated at 274, in which case the 
caller contact program 224 is repeated. Then, the program is terminated. 
FIG. 11 illustrates in greater detail the message review program 226 
initiated by an inquiry from the subscriber. The first step is a speech 
prompting message to the subscriber calling in as indicated by reference 
number 276. The speech prompting message prompts the subscriber as to his 
or her options for handling the messages recorded by the system. The 
subscriber then enters a choice as indicated at 278 which is followed by a 
first message playback operation 280. The entry indicated at 278 enables 
the subscriber to select the order in which the messages are played back. 
After the first message is played back, the system inquires as to whether 
such message is to be retained as indicated by reference number 282. If 
the message just reviewed is to be retained, the program proceeds through 
step 284 to a step 286 in which the speech prompting system asks the 
subscriber whether to contact the caller who left such message. On the 
other hand, if the message just reviewed is to be deleted, it is flagged 
for subsequent deletion as indicated at 288. 
After inquiry is made as to contacting the caller, the program either 
proceeds through step 290 to a confidential communication program 56" in 
which the subscriber attempts to reach the caller, or proceeds directly to 
the next message inquiry 292. The program then proceeds through step 294 
either to the beginning of another message review program or to a message 
deletion operation 296 wherein the speech prompting system informs the 
subscriber of the imminent deletion of the previously flagged messages. If 
it is confirmed that the flagged messages are to be deleted, the program 
proceeds through step 298 to a conclusion or to a message deletion 
operation 300 before the program is completed. 
Finally, FIG. 12 illustrates in greater detail the instruction selection 
program 228 which is used by the subscriber to program when calls are to 
be received, etc. The program is initiated by instructions given to the 
subscriber as indicated by reference number 302. The subscriber then 
enters a selection code as indicated at 304 to initiate a selection 
execution program 244' as hereinbefore described with respect to FIG. 7. 
Thus, depending on the entered code, one of the five instruction 
parameters 306, 308, 309, 310 and 312 is selected for entry into the 
instruction file 78 as hereinbefore described with respect to FIG. 2B. As 
an indication that more than five instruction parameters can be used, FIG. 
12 illustrates at 313 that other choices may be included in the system. 
The foregoing programs are stored within the memory unit 20a of the system 
controller 20 aforementioned. Such system controller furthermore provides 
additional services such as system diagnostics and maintenance to 
determine the state of the system and detects both subtle and major 
malfunctions. When such malfunctions are detected, the system operator may 
localize the source of malfunction and institute maintenance. Further, the 
system controller may provide for system expansion including the 
redefinition of parameters such as the number of ports, maximum message 
durations, etc. Management information and database management is also 
provided for by the system controller 20 to allow for assessment of system 
performance, enroll new subscribers, make corrections, deactivate service, 
profile subscriber and caller parties, locate popular subscribers who may 
be overloading the system, etc. 
With respect to the database management, the system controller controls the 
entry and readout from the database memories of memory unit 20a, which may 
consist of two files, respectively associated with the subscriber and the 
caller. Such files contain all information required for operation of the 
service, including phone numbers, subscriber reference numbers, personal 
access codes, callback reference numbrs, etc. Finally, the system 
controller also controls administrative operations as hereinbefore 
referred to, including accounting functions and support for credit 
verification. Support is also provided for the speech prompting and 
recording components of system 32, including prompting/response menus to 
be redefined on demand and to control the recording, editing, installation 
and removal of voice messages. 
The system hereinbefore described may also be implemented through an 
Audiotex 976 exchange, a service provided by various ones of the Bell 
telephone companies. Such an alternative billing arrangement will allow 
for a fee to be charged whenever a caller calls into the service without 
the added incumbence of entering credit card numbers, although a more 
flexible method of billing may be preferred by use of a credit card 
system. Thus, with the credit card billing method, the caller is still 
charged a fee upon entry into the system but the system has the option of 
charging follow-on fees for enrollment of the caller into the system, or 
time sensitive billing options. In this regard, each time a caller enters 
a new subscriber reference number, a standard fee can be assessed. The 
subscribers may also be charged for services provided by this system. For 
example, if a subscriber returns a caller's message, he or she can be 
charged in the same manner as a caller. Charges could also be assessed for 
various extended services such as custom message recording. 
Normally, a subscriber's credit card number will be entered into the system 
upon enrollment. This will allow the subscriber to rapidly return phone 
calls using the system, without the need for entering credit card 
information at the beginning of each session. When a charge is applied to 
a card, it must be authorized by a credit verification service. All credit 
card authorizations can be effected by a real-time method when the charge 
is incurred or by a batch method during off-peak periods through the 
credit verification port E. The use of credit cards allows uniform billing 
practices independent of the telephone utility local tariff policies. 
Whichever method of billing is utilized, the system can generate daily, 
weekly and monthly cash flow statements based on system activity. 
A key to the communication security provided by the system hereinbefore 
resides in the use of various identification code numbers such as the 
subscriber reference number, the personal access code, the caller 
reference number, and the call-back reference number. The subscriber 
reference number is associated with the subscriber's personal ad in a 
"personals" publication and is used by the caller to identify the desired 
subscriber. Such subscriber reference number is therefore in the public 
domain. However, when used in conjunction with a subscriber's personal 
access code, it allows only the subscriber to access the system services 
and messages. If a caller enrolls in the system, the caller will receive a 
caller reference number that will serve in place of the call-back 
reference number normally issued to a caller by the system. This will give 
a caller the same service as a subscriber. 
The subscriber reference numbers are periodically changed by the 
advertiser, such as monthly, weekly, etc. Typically, the subscriber 
reference number is composed of a date code and an index number. The date 
code corresponds to the formal release date of the ad and the index number 
is a unique identifier distinguishing the subscriber from other 
subscribers for placing ads during the same schedule period. 
The personal access code aforementioned is the subscriber's private code 
allowing access for various services provided by the system including 
message access. It is the key to the subscriber's privacy and should be 
known only to the subscriber. It is used in conjunction with the 
subscriber reference number to provide a unique access key to the various 
subscriber services. 
The callback reference number is created by the system and provided to 
callers when they leave a message for a subscriber. It is a unique number 
that the subscriber may use to identify particular callers when the 
subscriber is returning phone calls. 
The subscriber and caller database memories aforementioned, cover various 
fields. The subscriber reference number is stored in the database to 
identify each subscriber enrolled in the system and is issued when the 
subscriber places an ad in the publication. Also stored in the database is 
the phone number of the subscriber to whom calls are to be forwarded. The 
personal access code of the subscriber stored in the database file of the 
subscriber is a private access code used with the subscriber reference 
number as aforementioned. When the subscriber customizes the system as 
hereinbefore explained, various parameters selected by the subscriber are 
stored. Such parameters instruct the system about the subscriber's 
availability, how to handle messages, etc. Statistical data valuable to 
the subscriber is also stored in the subscriber database which includes 
the number of callers, etc. 
The caller database includes specifically different fields than those 
hereinbefore described with respect to the subscriber database. Such 
caller database fields include the callback reference number 
aforementioned which is a unique index identifying each caller who has 
left a message in the system, and the telephone number of the caller. The 
caller reference number, if appropriate, is a unique index that identifies 
each caller enrolled in the system as a subscriber. Also included in the 
caller database is a message pointer which points to the message left in 
the speech recording system for playback to the subscriber. When a caller 
is enrolled in the system, additional fields will be included in the 
caller database similar to those in the subscriber database. 
The foregoing is considered as illustrative of the principles of the 
invention. Since numerous modifications and changes will readily occur to 
those skilled in the art, it is not desired to limit the invention to the 
exact construction and operation shown and described, and accordingly, all 
suitable modifications and equivalents are intended to fall within the 
scope of the invention. For example, while the present invention has been 
described with specific reference to "personal ads", it could be used in 
other fields such as standard classified advertising and the like. That 
is, a subscriber can place a classified ad, can receive calls without 
divulging his or her telephone number, can return calls, and can simply 
discontinue the ad if, for example, goods for sale have been sold. 
Therefore, the intention is that the present invention not be limited by 
the above, but only be limited as set forth in the appended claims.