I believe that I discovered a method to generate several NP-complete problems. The NP-completeness proof is not immediately apparent to _me_. I did not find any reference in complexity literature to my problems and their $NP$-completeness. Such problems include the following posts:

[How hard is reconstructing a permutation from its differences sequence?][1]

[Recognizing sequences sortable by transpositions?][2]

> Is it fine to post question asking for proofs of $NP$-completeness of several problems?

[1]: http://mathoverflow.net/questions/135968/how-hard-is-reconstructing-a-permutation-from-its-differences-sequence

[2]: https://cstheory.stackexchange.com/questions/27858/recognizing-sequences-sortable-by-transpositions