How do I apply the responsive behavior in reference like lists not using the reference tag? For example in en:Template:Refbegin. Obviouly this template should be complemented with a new "Refitem" template adding some class to each item.
Topic on Talk:Contributors/Projects/Columns for references
You can't. Templates like that continue to be hacks that are not supported, I'm afraid.
Finally somebody else thinks these splitted templates should not be here, and it's not just me 
, Jdforrester (WMF).
In terms of improving accessibility, you might look at the work that User:RexxS was planning for w:en:Template:Reflist recently (look in /Sandbox2, I believe), to eliminate fixed numbers of columns (e.g., pages that always use three columns, no matter how narrow a reader's screen is, which can look very bad). That work has been overtaken by this change, but it might be an improvement over what the refbegin template is currently doing.
