MAGNOLIA-7228 allows deprecation for some definition items such as dialog def., component def., etc. It also can be used for page template definition.

Definitions app reports deprecated definition, which are referenced in another definition. (According to ilgun - we "look into registries" to find the usage and then check whether a "used" item is deprecated.) This means, if a dialog definition "dd" is deprecated, and this dialog is referenced from another definition "ad" - both "dd" and "ad" will be reported in the Definitions app.

However - deprecation of a page template definition is not reported in the problems tab of the Definitions app.