You are initialing now each page below by initial, and you are signing your name to the first page below my signature?
These latter, rashly or otherwise, had guaranteed its accuracy by initialing it.
"to mark or sign with initials," 1864, American English, from initial (n.). Related: Initialed; initialing.
"initial letter of a name or surname," 1620s, from initial (adj.) in a specialized sense "standing at the beginning of a word, sentence, etc."