Clue: Pointer initially ignored by soldiers and worker? That's ill-mannered (8)
Answer: IGNORANT
Explanation: Definition: ill-mannered
 "sign"(a pointer/an indicator) **minus its 1st letter**(initially ignored) **plus**(by) OR(abbrev. for "other ranks", non-commissioned soldiers) **plus**(and) ANT(an example of which is the worker/one in the worker caste).