There are some spam issues in the comments, so I had to disable comment editing for a short time. It'll be back once the spam bots are gone. FYI... they leave a comment with "great" and then edit in the spam stuff later, to get around the filter.
(It can be about following a regulation as well as about taking note of something in your vicinity. Best thought of as "opposite of to ignore". Always needs a direct object. Unlike "achten auf" it does NOT include the idea of "to take care")