"Marking Pen" achievement

[B0Tzerker]

Just played vs cpu with no bonus sets used. I marked a spare in 10 frames and did not get the achievement. Does this achievement require a mark in 11 or 12 frames?

If 12 frames is required then bowler must strike in 10th, 11th, and 12th frames.
If 11 frames is acceptable then bowler can spare in 10th and must strike in 11th.