Can I invent my own Slots?

[David Goodenough]

Gnucash seems to store a variety of things in key-value pairs known as 
slots.  Can I invent my own slot keywords and therefore add my own 
data into the GnuCash datastore in a way that GnuCash will be able to
return to me later and will not cause problems to normal operations?

Presumeably I should try to make sure my keywords are going to be
unique to me and not likely to be used by GnuCash, say by starting them
with my application name.

David