Related Clues:

• Edge or boundary
• Frontier of a country
• Margin along the edge
• A knight in mail was not in this
• Stick this on top of 20 down
• At last it gets blown
• There are letters after it
• You may have a job with the letters
• At last 13 across has one all on edge
• The bit of 9 down that one did not have to do
• That's a job for the letter
• Work for 21 across
• Perhaps where to stick the 20 down
• Stick to your job
• The sort of job that's only for the lettered