Redmine plugins sometimes add new fields in Redmine (in issues or other part of Redmine). It's obviously possible to add them in custom fields but in that case, administrators are not informed that the custom field is required for a plugin and might remove them. It would be nice to add a table such as custom_field_plugins that would link a custom field to a plugin name (the plugin would be in charge when it adds a custom field to indicate that this custom field is used by this plugin).

When a custom field is linked to a plugin :

• A new column in the Custom fields list (below) is added and indicates the name of the plugin (name given in the table custom_field_plugins) :

!CustomFileds.png!

• The button !Delete.png! is not present on these lines (to avoid deletion);

Advantages : be able to use "Custom fields" features on these fields (changing the name, the default value, the list of values, if it is required or not...).

!CustomFieldValues.png!

We could imagine that the table custom_field_plugins will permit to set the fields of Custom fields to be modifiable or not. For example a column name_read_only to 0 will not permit administrators to change the name of the plugin custom field. If the value is 1, the name of the custom field might be modified. And so on for description, possible values, projects...

It might permit to several plugins to use the same custom field too.