Sunday Times Prize Crossword 4535 Sunday April 28Th 2013

[mercedita]

Hi folks! Just two this time: 2Across Red skirts carried by prisoner (7) C _ I _ S _ N. I have got CRIMSON (red) and CRIM is "prisoner" but how does "SON" fit with "skirts"?

6Down: Completely useless if only half of it is included (2,4). I think it's IN FULL (completely) but can't see how the rest of the clue fits.

[bibblebub]

2a) skirts = RIMS, prisoner = CON

[frugalfred]

skirts is rims, carried by con = convict

[kettledrum]

Rims = skirts; con = prisoner

[Mamyalynne]

IF + NULL

[jollyroger66]

2) c RIMS on
6) in full

[frugalfred]

6d useless = null, + if, = in full, completely

[bibblebub]

6d) every other letter is NUL - i N f U l L

[jollyroger66]

how time flies !!

[mercedita]

Thanks for the 5A: I was going in the wrong direction. But I'm still puzzled by 6d: If the "completely" is IN FULL and uses the letters of "null" for "useless" + "if", what does the rest of the clue mean? I mean "only half of it is included". What's that?