When adding parameters, new parameter IDs may be added at the end or between other parameters

To deleting parameters they must be first marked using the P_OBSOLETE flag. For example:

   pb_onOff_OBSOLETE, _T("onOff_OBSOLETE"),
     TYPE_BOOL_TAB, ONOFF_COUNT, P_OBSOLETE, IDS_ONOFF_OBSOLETE,
     end,
 

Obsolete parameters are loaded normally, but after the post-load they are reset to default value, drop any references (which may free objects from memory).

The following tags may be removed from obsolete parameters: p_ui, p_default, p_range, p_accessor, p_validator.

The parameter can only be removed completely, if the plug-in only loads files where the parameter was already marked P_OBSOLETE. Attempting to load files where the parameter exists but was not marked obsolete is unsafe; hence complete removal of a parameter is not supported when you need to load files from multiple versions prior.