We allow ad hoc recorders to provide either counts or present as an abundance. However, but i didn't want to have multiple fields on the iform and neither did i want a completely free text entry I've thrown together a piece of regex (Indicia allows for regex to be used to filter information input into a field) which should (and seems to work!) allow only the word present (case insensitive) or a count to be entered (not preceded by 0).

Figured it might be useful for others so here you go;

/(?<![\w\d])present(?![\w\d])|^[1-9][0-9]*+$/i