I won't dig up the old thread... a good portion of the suggestions in it were satisfied. That's not to say you can't bring up the ones that haven't been, in this thread.
My new suggestion is: create C++98, C++03 and C++11 description pages in the Documentation, mentioning for each of the standards the publish dates, compliant compilers and perhaps a (short) list of major changes from the previous standard.
The reason for my suggestion is that I see in the Beginners forum that some members provide C++11 code, which will not compile unless the OP uses bleeding edge C++ compilers, while sometimes forgetting to say it is C++11 code altogether.
We should have an easy way of letting beginners know what standard our code is written in, by providing a quick link describing the standard.
I would go a bit further and suggest a code tag field, such as firstline:
[code std=c++98][/code]
Which will generate a small description box above the code snippet:
Although I think your suggestion is a good one, I think "This code is written in the C++98 standard. C++98" doesn't mean a lot to beginners. Perhaps a message like "Caution: This code snippet includes C++11 support", which links to a faq-entry about the different standards and which compiler flags to use?
Speaking of the faq, I believe it would be a good idea to do some work on the "Beginners/Homework" section.
A lot of problems in the beginners section seem to come by again and again, like how to check for even numbers for example.
I know it's a lot less personal to copypaste a link to a faq entry, but at least there will be some uniformity in the replies. The text would only have to be written once and would probably be more precise than someone typing the explanation for the third time in two days. I would be would be willing to write drafts for this if it saves someone else time.
Also, aside from people still not using code-tags, a lot of people don't even seem to bother formulating their question, or formulating it clearly. Perhaps there could be a few small highlights of this post: http://www.cplusplus.com/forum/beginner/1/#msg6680 on the "new topic" page.
Please don't read this as a rant, because it's not, just putting in my 2 cents.
I like both of your ideas. Maybe we can do as Catfish4 suggested-put a description box about the C++ standard implemented in the code. And then link those messages to an FAQ section as NwN suggested.
Also, common problems are posted again and again regularly. So, posting can be made a bit stricter like a warning message before the user posts saying "Don't post what's already posted and answered".
For instance, take the example that NwN gave. After reading the warning, if the user still tries to post "plz plz need help! how to check even numbers?". Then what can be done is that posts matching to "checking or finding even number" can be popped up before posting the question. If the user finds his/her answer, he can cancel the posting. That might help in multiple posts of same topic.