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.

perpendicular ‘perpendicular’

English

References: Alm. Toomer: 52; 62
Translation of:
Greek: κάθετος [Alm. Heiberg: I.10, 39:12; I.13, 71:4]
Greek: ὀρθός [Alm. Heiberg: I.12, 65:9]