I'll have to be brief as I'm supposed to be cooking the dinner

I'll add more later.
Customise -> New Tab -> Name it, e.g. 'Flags'
UNCLICK the 'Show most commonly used items'
CLICK ' for advanced users' (for indeed you are now an advanced user!)
CLICK the little right-arrow thingy to send it to the right
TYPE a name for this ROW (eg 'Births')
CLICK Part 1
TYPE a label, eg 'Birth Certificates' (probably best to put the name of the flag here)
PRESS 'Select'
PRESS the little '+' next to FLAGS
Select a flag and press OK
Leave the other settings for now.
Click OK
Click OK again if you have no more to add, otherwise add another ''
The tab will now appear with your flags on it.
PART 1 Items go on the left, PART 2 on the right, if you are happy to just have a list of them, only fill in the PART 1 bit.
Hope this helps, sorry it is rushed, I will edit tomorrow with more steps.