user2869: Sometimes I get confused about this, should I tag my question with toaru-majutsu-no-index or toaru-kagaku-no-railgun? And I ended up using both tags for my question.
Based on the question about How are "A Certain Magical Index" and "A Certain Scientific Railgun" connected?, these two anime are the same. Or so I understand the answer, maybe I got it wrong?
And I saw a question about Should multiple continuities have individual tags? and according to Kuwaly's answer,

For Neon Genesis Evangelion, and in general, I think having a policy of fewer-is-better should be used when regarding tags

Don't you think the same policy should apply for Railgun and Index? Can't we just make a synonym or something?

user122: I don't think that it's a good idea. Index and Railgun are two series that play in the same universe and share some characters, but that's all (only one arc is happens in both animes yet (and doesn't share much, actually), the others are completely independent. I don't know about the Daihasei Festival Arc, but it seems like they are independent, too). One could have seen Railgun without knowing of Index (or the other way round) and can answer the question if it is really about Railgun. 
Index and Railgun are just too distinct to be handled with one tag, imo. 

2869: <p>Sometimes I get confused about this, should I tag my question with <a href="https://anime.stackexchange.com/questions/tagged/toaru-majutsu-no-index" class="post-tag" title="show questions tagged &#39;toaru-majutsu-no-index&#39;" rel="tag">toaru-majutsu-no-index</a> or <a href="https://anime.stackexchange.com/questions/tagged/toaru-kagaku-no-railgun" class="post-tag" title="show questions tagged &#39;toaru-kagaku-no-railgun&#39;" rel="tag">toaru-kagaku-no-railgun</a>? And I ended up using both tags for my question.</p>

<p>Based on the question about <a href="https://anime.stackexchange.com/questions/2675/how-are-a-certain-magical-index-and-a-certain-scientific-railgun-connected">How are &quot;A Certain Magical Index&quot; and &quot;A Certain Scientific Railgun&quot; connected?</a>, these two anime are the same. Or so I understand the answer, maybe I got it wrong?</p>

<p>And I saw a question about <a href="https://anime.meta.stackexchange.com/questions/308/should-multiple-continuities-have-individual-tags">Should multiple continuities have individual tags?</a> and according to Kuwaly's answer,</p>

<blockquote>
  <p>For Neon Genesis Evangelion, and in general, I think having a policy of fewer-is-better should be used when regarding tags</p>
</blockquote>

<p>Don't you think the same policy should apply for Railgun and Index? Can't we just make a synonym or something?</p>
 122: <p>I don't think that it's a good idea. Index and Railgun are two series that play in the same universe and share some characters, but that's all (only one arc is happens in both animes yet (and doesn't share much, actually), the others are completely independent. I don't know about the Daihasei Festival Arc, but it seems like they are independent, too). One could have seen Railgun without knowing of Index (or the other way round) and can answer the question if it is <em>really</em> about Railgun. </p>

<p>Index and Railgun are just too distinct to be handled with one tag, imo. </p>
