Labels are a delicate matter inasmuch they must be unique throughout all the Blender Documentation Project to allow for cross references from one chapter to another etc.
It is thus higly adviceable to stick to a given standard:
For Core documentation
PID.CID.[F|T|E|D|L].AID.userdefined
For Tutorials
TID.AID.userdefined
Where
PID is a two letter Pubblication Identifier;
CID is a three letter Chapter identifier;
[F|T|E|D|L] is a letter defining the Type of object labelled, that is:
Figure;
Table;
Equation;
Document Data (i.e. a Section, subsection, paragraph etc);
Listate;
AID is a three letter author identifier;
userdefined are (up to) ten letters up to the author to define;
TID is a three letter tutorialidentifier;
PID and CID are provided by the DocBoard.
TID and AID are to be agreed between the author and the DocBoard in a preliminary phase.
The userdefined is completely up to the author, who is responsible for keeping the whole label unique.