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.

ἀκτίς‘ray’

Greek. – Grammar: n.

References: Alm. Heiberg: II.5, 99:2
Translated into:
Arabic: شعاع [Alm. MS Leiden: f. 16r. – Alm. MS Tunis: 21b.16-17]
Modern translations:
English: ray [Alm. Toomer: 80]