Canadian units that fought in Afghanistan are being considered for battle honours by the Harper government, which is casting around for ways to commemorate the conflict as it draws to a close after more than a decade.

A memorandum to Prime Minister Stephen Harper, obtained by The Canadian Press under access-to-information legislation, lays out the options for recognizing individual regiments for specific battles and for the overall war itself.

The country's top civil servant, Wayne Wouters, said awarding of battle honours has deep historical roots and must be done in a thorough manner to ensure units are properly recognized.

Historian Jack Granatstein says the fact most of the fighting was against Taliban militants, who chose short hit-and-run attacks and faceless, remotely detonated bombs, may complicate the process but ultimately won't stop the acknowledgement.

He says there is precedent for honours arising from a guerrilla war, pointing to the fact Canadian units, which fought the Boer War between 1899 and 1902, received recognition.

Granatstein says the bigger question is how far the Harper government is prepared to go in publicly commemorating the Afghan war, which divided the nation.