[Glade-users] Catalog documentation confusion

[Tristian Celestin]

I am reading the documentation regarding adding catalogs to Glade (https://developer.gnome.org/gladeui/unstable/catalogintro.html). 

What does it mean to "optionally provide code support"? I understand that a catalog can provide icons so that one can identify new widgets in the palette. I also understand that a library implementing the widget can be provided so that properties and signals can be identified. Is the "code support" referring to this latter feature, or is it something else?