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.

مثال ‘example’

Arabic

References: Alm. MS Leiden: f. 14v. – PH Morelon: I.2:5, 19:2
Translation of:
Greek: ὑπόδειγμα [Alm. Heiberg: II.2, 89:19]
Greek: παράδειγμα [PH Heiberg: I.2:5, 74:1]
Modern translations:
French: modèle [PH Morelon: I.2:5, 18:3]
German: Beispiel [PH Nix: I.2:5, 75:1]