Yes, having some 'attributes' field could be useful.

BTW, the matter I was talking about "unified recommendations for extending the database" is that previous developer has added a number of fields to existing tables (answers, users etc) instead of creating new tables.
Not only it's incompatible, but also I have to write php code to parse his sql "exports" to insert survey in normal database. Such things happen :-)

Thibault Le Meur  wrote:
We currently have 'attributes' for questions: this is very usefull
when we want to add small features without having to change the db

Would it be possible to have such things for other objects (for
instance surveys, groups) ?