Codes used in several countries
HO on a licence plate
HO is an area code in 4 countries. The plate's style and country code tell them apart.
Austria
HO 123ABCode details →Horn (Lower Austria)
Germany
HO-AB 1234Code details →Hof (Bavaria), Hof (Bavaria)
Greece
HO-1234Code details →Xanthi
Ukraine
HO 1234 BCCode details →Ternopil Oblast