[...] "faithfulness" constraints demand that the output be as close as possible to the input, along all the dimensions upon which structures may vary.
- McCarthy & Prince (2004), Pag. 370

[...] the full schema for a faithfulness constraint may include such specifics as these: the element preserved, the dimension of derivation along which the two structures are related, the "direction" of inclusion along that dimension (as in the contrast between MAX and DEP), and the morphological domain (stem, affix, or even specific morpheme) to which the constrain is relevant.
- McCarthy & Prince (2004), Pag. 376