We changed the wording of the text to make it more comprehensible.
The instructions should be easily comprehensible to parents.
His French was barely comprehensible.
The system is perfectly comprehensible to most people.
a book that is comprehensible only to specialists - книга, доступная только специалистам
понятный, постижимый, вразумительный
a book that is ~ only to specialists - книга, доступная только специалистам