Since my first visit to Hawai’i, in 1982, diacritics, particularly the macron, e.g. ā (Hualālai), have appeared a lot. Also making more of appearance are the use of apostrophes, e.g. Hawai’i. They seem to be used without rhyme or reason. New signs have them, or don’t & old signs have not been redone. It was confusing until I found this on the University of Hawai’i site:
“The Hawaiian language uses two diacritical markings. The ‘okina is a glottal stop, similar to the sound between the syllables of "oh-oh." In print, the correct mark for designating an ‘okina is the single open quote mark. The kahako is a macron, which lengthens and adds stress to the marked vowel, e.g. Hualālai. For example 'pau,' depending on placement of ‘okina and kahako, can mean completed, smudge, moist or skirt.
The State of Hawai‘i and University of Hawai‘i strongly encourage use of Hawaiian diacritical markings. (See UH Style Guide.) Technology, however, is still catching up.”
