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.

the tip of the shadow ‘tip of the shadow’

English

References: Alm. Toomer: 80; 82
Translation of:
Greek: τὸ ἄκρον τῆς σκιᾶς [Alm. Heiberg: II.5, 99:1]
Greek: τὸ τῆς κορυφῆς (τῆς σκιᾶς) ἄκρον [Alm. Heiberg: II.5, 101:5-6]