[Koha] Problems with hidden option in the marc subfileds.

Hi Can anyone let me the following: 1. When you are editing the MARC subfields, in the editor constraints, there are various options out of which one of them is 'hidden'. In the 2.2.4 version it allows you to either put a tick or leave as it is. 2. But in the demo version i.e circ/liblime, when you go to biblio framework and then go to the edit marc subfields, the 'hidden' field in the editor constraint allows you to put numbers like 1, 2, -1, -5 etc. Why is it so? Also what do the numbers after 3 and negative numbers like -5, -6 signify? For eg: 1 means hidden in opac, 2 means hidden in editor. What about the remaining? thanks --trupti