Every Property has it’s own constants.
Popular constants are:

everytime a new object is created, this property will have an initial value.
(not for existing objects Рthey will stay null)
if a LOV ist attached, the inital value have to be conform with it.

true = if you “revise” or “save as” an object, the new objects property will have the same value.
false = new property value is null

true = user can edit this value
false = only a workflow can edit this value

you can combine a string property with some other property text like $object_name”-“$item_id

for storage type double – see this post