Koha doesn't currently have a single point of truth for documentation of notices and slips, which has lead to a proliferation of markup syntaxes, especially in regard to repeating detail, e.g. DUEDGST/PREDUEDGST: <<items.content>> ODUE* <<items.content>> or <item> </item> CHECKOUT/CHECKIN/RENEWAL ---- Detail here ---- These have been documented in https://wiki.koha-community.org/wiki/Customising_Notices_and_Slips#Notice_Ma... , but this has gotten out of date as new notices get added in each version of Koha. Work to be done: Add Koha/Notices.pod which will document the following for each notice in the Letter table: * Letter Code * Source file where the notice is populated * Logic that triggers the notice * Detail syntax (if any) * Available data (tables and substitutions) * Message transport restrictions The output from this pod should be used as the basis for the Koha user documentation. See Bug 21858 and https://wiki.koha-community.org/wiki/Notice_documentation_rfc