Can I ignore the case/diacriticals/etc when working with a string?

Applescript FAQ Text Manipulation
#1

Yes. You can use special statements called ignoring or considering statements.

You can ignore the following attributes: case, diacriticals, expansion, hyphens, punctuation and white space.

By default, AppleScript ignores only the case of strings. Example usage:

ignoring case and diacriticals
	"castle" = "CÃ¥stle" --> true
end ignoring

To take into consideration some attributes, simple replace “ignoring” with “considering”.