Subsp. or ssp. ?

[Martin Dube]

On   Mon, 22 Jan 1996, Robin Leech wrote :

> By sort of an international agreement, there are some abbreviations that
> are used in both botany and zoology.  They are these:
>
> 1.  species (singular) =      sp.
> 2.  Species (plural)   =      spp.
> 3.  subspecies (sing.) =      ssp.
> 4.  subspecies (pl.)   =      sspp.
>
> Robin Leech
>
But, the ICBN is the result of an international agreement, isn't ?

Martin