Is っ used with all consonants or only some of them?


I need to make simple romaji to hiragana conversion for a word based game.
When implementing long consonants, I ran into a potential problem of ambiguous
conversion. My question is, **is っ used with all consonants (`kgsztdcnhbpmr`)
or could it be that some combinations are never actually used?**




I can't believe I missed it, but those are actually listed on
[Wikipedia](https://en.wikipedia.org/wiki/Sokuon). So according to Wikipedia っ
cannot be used with:

  * n
  * m
  * r
  * w
  * y

Even if there are cases where っ appears in front of those consonants, those
are likely irrelevant to my romaji to hiragana conversion.




I can't believe I missed it, but those are actually listed on
[Wikipedia](https://en.wikipedia.org/wiki/Sokuon). So according to Wikipedia っ
cannot be used with:

  * n
  * m
  * r
  * w
  * y

Even if there are cases where っ appears in front of those consonants, those
are likely irrelevant to my romaji to hiragana conversion.

