Date of deprecation. Must be in YYYY-MM-DD format e.g. 2024-11-13.
Tested against regex ^\d\d\d\d-(0[1-9]|1[012])-(0[1-9]|[12][0-9]|3[01])$
.
Thanks to Vinod at https://stackoverflow.com/a/22061879 for the regex.
Should contain the reason for deprecation and what to use instead in what contexts.
Contains information about the deprecation of a localized string key, including the date of deprecation and the reason.