three libtools - portupgrade question

[Ben Paley]

Hello,

I've got three versions of libtool on my system:

bash-2.05b$ pkg_info | grep libtool
libtool-1.3.5_2     Generic shared library support script (version 1.3)
libtool-1.4.3_2     Generic shared library support script
libtool-1.5         Generic shared library support script
bash-2.05b$

Does it need to be like that? or can I safely do something like

portupgrade -o libtool13 -f libtool-1.5.6

and

portupgrade -o libtool14 -f libtool-1.5.6

Thanks for your help,
Ben