Small gap at top end of some golf shafts

[golfH2zero]

1. Does anyone know why some graphite golf shafts come with a small u shaped
gap (anywhere from 1/2 centimetre to over a centimetre) at the top of the butt end?

2. Could this have a negative effect on a golf shaft extension i.e more stress/more liable to splitting?

3. I have seen some specs of coloured paint (near the butt end) on some new shafts for sale. Is this the golf
shaft extension code?

Cheers. Comments appreciated.

 

[jim8flog]

If you mean this the u shaped gap is probably where the shaft is held in manufacture and will be cut off when the shaft is trimmed to length