Claudio,
Fantastic, thanks for your clearheaded guidance. The error unsurprisingly was in the only bit that I hand-typed. I had accidentally inserted a space between the '-' and 'url'.
Silly boy!
That has very nicely removed the xowiki package node from the breadcrumb trail. However it still leaves the main root node as follows:
Main : Home
In this case Home is the current page, and Main is a link to the currently displayed page (i.e. Home). This is clearly redundant.
Is it possible to change the -url declaration to in order to skip both superior levels, and if so can that be done only for non-logged in visitors?
Richard.