System Code GL01.1 and GL01.2

Barb
We use the system control for most of our Lawson subsytems.  The one benifit I know is that you can set valid entry dates when you set the cntrl to Y.
Example we only allow people to enter into AP and AR for the current month and the next month.  IF they try to enter with an effective date 3 months from now the GL System Control will send an error and not let them add an entry with a gl effective date beyond what was set on GL01.2.
The GL01.2 flags will flip for a susbsyem close when the susbsytem close job has run, it is usually a 195 or 199 job. example AP close is ap195. 
It is true that if you set a flag to Y on GL01.2 and the subsytem does not close GL in turn will not close.  We have not had too many problems with this.  More of a training issue to make the people responsible for each subsytem make sure to check that they truely did close before we try to close GL.
We are on 8.1 but I would think it would work the same way on 9.0 I havent heard that it would be any different.
Hope that helps

It appears to work the same way in 9.0. We use it in AP, IC, and PO. It seems to prevent errors, be it fat finger mistakes or users trying to to enter data into a period that they should not be posting to.