"Which search engines support …" questions?

Question

I wonder if it’s okay to ask questions in the form of "Which search engines support …?" on Webmasters SE?

Examples:

• Which search engines parse RDFa, and which vocabularies do they support?
• Which search engines [don’t] honor robots.txt?

Such questions would not be only about the big well-known search engines, but especially about smaller/new search engines, where such information is hard to find if you are not checking all of them manually. I think such a summarized resource would be very useful, and because everyone may edit answers, there is the chance that this resource will grow and be up-to-date.

If such questions are on-topic, would it be okay to require "1 search engine per answer"? I think there could be a community wiki answer that links to all valid answers (= search engines), which could be the accepted answer. Because otherwise the first "big" answer which contains several search engines would be the accepted one, while valuable answers containing only one or a few search engines might follow.

Or should the whole question+answers be a community wiki? Then there could be only one answer which gets updated regularly; or here also 1 search engine per community answer?

Or are such questions not welcome here?

If I don’t run into any headwinds, I would try and ask the RDFa question. I think the best format would be "1 search engine per answer" (normal, not CW answers); and a single community wiki answer that links to all other valid answers. In the hope that each author curates (new vocabularies etc.) his/her answer (with the help of user comments); if not, the answer could be edited by the whole community and become a community wiki.

Answer 1

We just had the question: Does Google ignore robots.txt? which is certainly on topic. I checked for duplicates and to my surprise, I found that nobody had asked it here before. Asking the same thing about other search engines would be on-topic because it is useful for running your website.

Similarly, It would be appropriate to ask about support for semantic markup from a particular search engine. It would directly relate to running your website.

As you note, asking "which search engines" is very open ended. Questions that ask for a list of things are usually not good questions. Asking about one search engine at a time would be much better. As Robert Cartaino says on Stack Exchange Meta:

Big List™ breaks down the whole premise of why we created these sites in the first place — to vet and deem the information contained in the post as useful.