From either the Transient casual-editkit-main-tmenu or via key binding C-c s, invoke the menu casual-ispell-tmenu to get menu of commands shown below:
If no text (region) is selected, then Ispell will behave with respect to the cursor (point) position.
For certain modes, casual-ispell-tmenu will add the following two menu items:
The modes are determined by the customizable variable casual-ispell-comment-or-string-predicate which references a predicate function. By default this function is casual-ispell-comment-or-string-p which tests the major mode to be one of the following:
prog-mode
bibtex-mode
conf-mode