Celtic have been cleared of any rules breach over an 'offensive banner' at Parkhead last year.
The Scottish Professional Football League launched an investigation after supporters displayed a large 'H' banner, said to represent part of the Maze Prison in Belfast known as the H Block, at the game against Aberdeen on November 23.
Below the symbol fans held aloft a section of lyrics - 'They fought and died for their wee bit hill and glen' - from Flower of Scotland, widely played as Scotland's national anthem ahead of sporting events.
A spokesman for the governing body said: "The SPFL has concluded its investigation into the appearance of a large 'H' banner on 23 November 2013 during Celtic's home match against Aberdeen.
"SPFL regulations forbid 'words or conduct or displaying any writing or other thing which indicates support for, or affiliation to, or celebration of, or opposition to an organisation or group proscribed in terms of the Terrorism Act 2000'.
"The SPFL found that the banner was offensive and breached the SPFL's rules. However, Celtic FC were able to demonstrate that they had taken all reasonably practicable steps to prevent the banner being displayed at Celtic Park.
"As a result, it was determined that there was no evidence of any breach of the SPFL's rules by Celtic FC.
"The SPFL wishes to reiterate, for the avoidance of doubt, that any banners indicating support for, or affiliation to, or celebration of, or opposition to an organisation or group proscribed in terms of the Terrorism Act 2000 or are otherwise offensive, are not welcome at SPFL grounds."
Four days after the 'H' banner, another display depicting hunger striker Bobby Sands and Scottish Nationalist icon William Wallace - on show during the Champions League tie against AC Milan - was deemed 'illicit' resulting in a £42,000 fine from UEFA.
Celtic have since disbanded the Green Brigade, the section of the crowd responsible for the banners, and have pleaded with fans to keep all political views away from the ground.