Should adding redundant but related tags be encouraged or discouraged

Question

...when earning tag badges could be an influence?

^{(I'll try to keep this short)}

I saw this question that was initially tagged c#, xml and xml-serialization. It was looking for a simple way to decode some XML strings. It was eventually answered by polishchuk where he pointed to a method that helps with this. It was upvoted and accepted. Afterwards, he retagged the question adding the .net tag.

To me that looked strange, I wouldn't add tags unless it made the question clearer or is otherwise absolutely needed. In this case, it was redundant since the c# tag usually implies .net and there were no other constraints given by the asker. So I looked at his history with the tag and every single answer he has under the .net tag that I have seen had the tag added by him after he answered. He's only been a member for just over a month and already has a bronze .net badge. It feels sketchy to me. It's certainly a related tag and is applicable but is it a necessary one?

I have a lot of other answers which I could also retag accordingly and I'd probably earn a lot more badges too. In fact everyone who participates regularly would probably benefit from this. But I feel that doing so would cause badge inflation.

Should we be adding tags like this or should we not?

I generally don't retag questions unless there is something terribly wrong with the current tags or I do it as part of normal editing duties.

_{I don't want to single this person out so I'm withholding his identity for now. Hopefully my explanation is enough to understand the situation.}

Answer 1

No, you should not add tags that are a superset of the question.

Unless the question is specifically language agnostic and explicitly asks for replies in VB.NET, C#, F#, IronRuby, and anything else that runs on the .NET CLR / DLR -- which is extraordinarily rare -- then you should assume that when someone tags a question c# they actually wanted C# code in return.

Shocker, I know.

Answer 2

Adding such tags is not just noise. It can increase searchability.

If someone wants to know how to frobnicate in .NET he might enter "frobnicate .net" into the search box. He might not find a question that doesn't mention .NET and is only tagged c#. If the question is tagged with .net as well, then he might find it (and he probably doesn't care too much if the answer is C# or not).

Answer 3

While C# is a .NET language, if the question doesn't ask about .NET itself, the .net tag isn't necessary. However, if the question dose pertain to the library, which is related to .NET in general, the tag probably belongs in the question.

While it would not be useful to add tags that don't directly pertain to the question, one needs to look at each question and see whether the topic specified by each tag is directly relevant to the question.