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.

arc ‘section’

English

References: Alm. Toomer: 91
Translation of:
Greek: τμῆμα [Alm. Heiberg: II.7, 118:12. – PH Heiberg: I.9:7, 84:10]
Synonyms:
section[PH Hamm: I.9:7, 52:10]