On Wed, Sep 15, 2010 at 10:34:31PM +0100, Chris Rowley wrote:

> So is \reserveinsertssss a primitive of e-TeX?  Or a sort of 'plain e-TeX'
> macro?

\reserveinserts is a macro of etex.sty:

| %% And we define \reserveinserts, so that you can say \reserveinserts{17}
| %% in order to reserve room for up to 17 additional insertion classes, that
| %% will not be taken away by \newcount, \newdimen, \newskip, or \newbox.
| 
| \outer\def \reserveinserts#1%
|  {\global\insc@unt\numexpr \et@xins \ifnum#1>\z@ -#1\fi \relax}

Yours sincerely
  Heiko <[log in to unmask]>