>attributes may be assigned globally in template. one of the last
>additions to the inferface before we made it publically available for
>testing was the + sytnax:
>
> foo =+l \foovar
>
>sets the variable \foobar (which should be a register in the above
>case) globally

[It is surprising how one is unable to find something, except when
one has got already the answer. :-) ]

Well, forget my previous message, and change istead the attribute
declaratios:

\DeclareTemplate{contentsobject}{JB1}{7}{
  pre-action       =+f0 []         \COpre@action,
  post-action      =+f0 []         \COpost@action,
  decls            =+f0 []         \COobject@decl,
  left-margin      =+l  [15pt]     \@tempdimd,
  right-margin     =+l  [\@pnumwidth]  \@tempdime,
  right-adjust     =+l  [\ttl@corr]    \@tempdimb,
  label-format     =+f0 [\thecontentslabel]  \COnumber@format,
  label-width      =+l  [15pt]     \@tempdima,
  title-format     =+f1 [#1]       \COtitle@format,
  title-format-nolabel =+f1 [\COtitle@format{#1}]  \COtitle@format@nolbl,
  page-format      =+f1 [#1]       \COpnum@format,
  leaders-text     =+f0 [.]        \COleaders@action,
  leaders-width    =+l  [1pc]      \@tempdimc
 }
etc.

\bye
Javier