411 REFERENCE · Wiktionary
A. O.
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
Appendix:Variations of "ao"
French
Proper noun
fr Afrique orientale (East Africa), used as an overprint on stamps of Belgian Congo in 1918 for use in Belgian occupied German East Africa
fr Geographic abbreviations Overprints