Bản mẫu:Jcttop/doc

=== Usage**
This template creates a WP:RJL-compliant header for junction lists or exit lists. It can be combined with jctint to create a complete, standardized table for a route. To use this template to create the header for a regular exit list, use |exit after the template name before any additional parameters. If the table needs to display a column for old exit numbers, use |old after the template name instead. If a freeway has named interchanges, like the Pennsylvania Turnpike, add |name after either |exit or |old.
This template accepts these parameters, all optional:
*location_ref: a reference for the locations in the table. The reference will be placed next to the "Location" heading
*length_ref: a reference for the mileposts or kilometer posts in the table. The reference will be placed next to the "mi" or "km" heading
*exit_ref: a reference for the exit numbers in the table. The reference will be placed next to the "Exit" heading if being used in an exit list. (It will be place next to the "New exit" if being used in an exit list with old exit numbers.)
*old_ref: a reference for the old exit numbers in the table. The references will be placed next to the "Old exit" heading if being used in an exit list.
*name_ref: If a freeway has named interchanges, like the Xa lộ thu phí Pennsylvania, this can be used to reference the names column. The reference will be placed next to the "Name" heading.
*dest_ref: a reference for the destinations in the table. The reference will be placed next to the "Destinations" heading.
*state: the two-letter postal abbreviation of the state that the road is in if the route is in a single state
**state_col: for multi-state/provincial junction/exit lists, set to State to display a "State" column, Province to display a "Province" column, or State/Province to display a "State/Province" column.
*county: the name of the county that the road is within (borough and parish  for Alaska and Louisiana, respectively) The presence of both parameters will remove the county column from the header and generate the following note above the table: "The entire route is in  County." The county will be wikilinked appropriately.
*nocty: specify "nocty=yes" to disable the county column without producing the hatnote above the table. Use this when it is necessary to create a custom hatnote, such as when an entire route is on a county line. If the location column also needs to be suppressed, use "location=none" as well.
*location: the name of the location that the road is within, if it's in a single location. The presence of the location parameter will remove the location column from the header and generate the following note above the table: "The entire route is in  County." The location and county will be wikilinked appropriately.
**area: used to disambiguate between town, city, village, etc.
**ctdab: further disambiguation by county. Enter "ctdab=yes" if needed.
*unit: specify "unit=km" for the unit to be given in kilometres (as when referring to roads in areas where miles are seldom used); default is miles.
*unnum: set to yes if being using in an exit list that has unnumbered exits. It will add "All exits are unnumbered." as a note above the table. It also should be noted that if the "county" and/or "location" parameters are filled, the note will appear after the note from the other said parameters.
*former: specify "former=yes" if the article route is historical (in other words, no longer exists). This will change the note to read "The entire route was in..." or "All exits were numbered." This parameter has no effect if "county" or "unnum" are not specified.

**See also**
jctint, a template for creating junction list entries
*jctbtm, a template used to add the bottom of the table
*NYinttop, a sub-template of this one that automatically fills in "NY" for the state parameter
*PAinttop, a sub-template of this one that automatically fills in "PA" for the state parameter