The word "diacritical" refers to marks or signs added to letters in certain languages to change their pronunciation or meaning. These marks act as a guide to give specific sounds or indicate any modifications to the original letter.
-- Write 10 words frequently mispronounced and indicate correct pronunciation by use of diacritical marks and by syllabication. (californiapolicycenter.org)
The handle has numbered adjustment settings between 1 and 6 divided by diacritical marks between each number. (mistershaver.com)
The class will read transliterated text (English letters with diacritical markings) alongside the original script. (prairieyoga.org)