This was a genuine question. Gaster's handwriting contains random uppercase letters and actual mispelled words lol (he usually scribbles them out, though, if he isn't sure of the spelling). Gaster also avoids all punctuation except for periods.

Oh, wow! He gave up on his stance on sign language rather quickly? I think it's mainly because of his "irritablility" he mentioned in conjunction with how short he gets with Papyrus. Also in conjuction with how short he is in general.