Should versus MUST within the ARIA spec regarding interactive widgets?

I was reading through the spec, 
http://www.w3.org/TR/wai-aria-1.1/
and noticed that within all of the interactive widget roles, such as Menu, Menubar, Listbox, Grid, etc., the following text is used:

"authors SHOULD manage focus of descendants for all instances of this role, as described in Managing Focus."

However, in section 2.3 Managing Focus, at
http://www.w3.org/TR/wai-aria-1.1/#managingfocus
It states:

"Content authors are required to manage focus on the following container roles:" ... Which is missing Tablist/Tab by the way.

So, regarding the use of SHOULD, it appears that managing focus for these widget types is optional?

Personally, it would make more sense to make this a MUST, because I see way too many developers adding ARIA attributes and completely ignoring the necessary scripting behaviors to make them work properly.

Received on Monday, 15 December 2014 09:00:24 UTC