PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

agens ‘active’

Latin. – Grammar: part..

References: Alm. Gerard: I.1:17, f. 1vb:45
Translation of:
Arabic: الفاعل [Alm. MS Leiden: I.1:17, f.3r:9]