For some of the question types it would be good to be able to create groups of answer options and give these a header.

A simple example, a list with countries:

Brazil
Argentina
Venezuela
...
Germany
UK
Spain
...
China
Japan
Indonesia
...

Now it would be good to be able to group some of the options together and give them a header, like this:

South America
Brazil
Argentina
Venezuela

Europe
Germany
UK
Spain

Asia
China
Japan
Indonesia

Of course the headers should not be an answer option, just plain separators.

It would also be good, to be able to randomize the answer option groups, as well as the answer options within the groups. But I will open a new feature request for that.

You have this possibility in List Dropdown Question : category_separator.

Maybe add this ablility to other question type.

The feature is already there, we just need to port it to other question types. Shouldn't be hard to code.

Well, sounds good to me. Never ran into this feature, as I hardly use the dropdown feature, as it is not very comfortable for respondents, especially with long lists.

I think it would be nice to have this for all questions where you can have a longer list of answer options.

Had a quick look at the category_separator and I think it is not as universally usable as I would like it to be. Sometimes the answer category headers can be longer and then the format can be quite annoying:

Just an example from one of my surveys. One of the category headers is "Searching for information about..."

Right now you would have to add:

Searching for information about... : blablablub
Searching for information about... : blablbabla
etc.

Would be quite long I think.

I don't think it's that complicated to use it with longer strings.

Different question: Since the text is inputted at the answer editing screen, multilingual surveys shouldn't be a problem?!

Well, I don't think it is complicated, but if the header is pretty long, all you will see in the text boxes is the header, and not the answer option, which can make it difficult to work on the survey. But of course, this is a minor thing.

I don't think it will be any problem for multilingual surveys. But as I usually don't use multilingual surveys, but rather create one survey per language, I am not very savvy in this area.