# Writing deprecated NTFS fares
## Introduction
This document describes how fares specified in Navitia Transit Model are transformed into a [NTFS fare feed](https://github.com/CanalTP/navitia/blob/dev/documentation/ntfs/ntfs_fare_extension_fr_deprecated.md).
In this initial version:
* only tickets on origin-destination stops are taken into account
* only constraints on physical modes are taken into account (if a ticket is specified for a specific line or network, this information is ignored)
* the validity duration and the transfers allowed for a ticket, if specified, are ignored
* tickets specified in a currency different than EUR are ignored.
These limitations will be adressed in a later version.
In the following, the NTFS fields that are not specified are ignored and not detailed.
### prices.csv
As a reminder, this file has no header and the order of the NTFS fields must be respected.
| \*clef de ticket\* | Ticket | ticket_id | |
| \*date de début de validité\* | Ticket | start_date | Starting date of the validity period of the fare structure in the form YYYYMMDD. |
| \*date de fin de validité\* | Ticket | end_date | The date after the specified end date in the form YYYYMMDD. |
| \*prix\* | Ticket | price | The specified value is converted into euro cents. |
| \*name\* | Ticket | name | |
| \*champ ignoré\* | | | This field is explicitly left empty. |
| \*commentaire\* | | | This field is explicitly left empty. |
| \*devise\* | Ticket | currency_type | The value is set to `centime` provided that the currency used for the ticket is EUR. |
### od_fares.csv
| Origin ID | OD Rules | origin_stop_area_id | The id is prefixed with `stop_area:`. |
| Origin mode | | | Fixed value `stop`. |
| Destination ID | OD Rules | destination_stop_area_id | The id is prefixed with `stop_area:`. |
| Destination mode | | | Fixed value `stop`. |
| ticket_id | OD Rules | ticket_id | Link to the ticket specified in [prices](#pricescsv) |
### fares.csv
For each distinct physical mode specified in `OD Rules`, a row is created in this file in order to allow to represent transitions for the origin-destination tickets.
| avant changement | | | Fixed value `*`. |
| après changement | OD Rules | physical_mode_id | The id is prefixed with `mode=physical_mode:`. |
| début trajet | | | This field is explicitly left empty. |
| fin trajet | | | This field is explicitly left empty. |
| condition globale | | | Fixed value `with_changes`. |
| clef ticket | | | This field is explicitly left empty. |
