Extra entries outside the matrix

??=[entries.extra] It is possible to put extra entries in your diagrams that are not part of any `entry' of the matrix created by |&| and |
|. This is done with the `excursion command'
\begin{defs1} \vert\save\vert $t$\ \vert\Drop\vert \vert{\vert''stuff''\vert}\vert \dots \vert\restore\vert \dots \end{defs1}
where t should be a target in one of the formats described in section ??[arrows.targets] and "stuff" may be anything that can appear in an ordinary entry.

This will create a `pseudo entry' at t containing ||"stuff"||: any -pic commands following before || will be relative to the pseudo entry rather than to the entry hosting the excursion. Here is an example, using an entry relative position as target:
\begin{code} \diagram A \drline & \save +<3cm,0cm> \Drop{\Text<8pc>{% This i... ...ram.}} \lto \dto \restore \\ & B \rline & C \rline & D \enddiagram \end{code}
will typeset

$\displaystyle \NoCompileAllDiagrams$$\displaystyle \docode$

It illustrates how a `down' arrow does not necessarily have to point particularly straight down—in this case because it is based in the displaced pseudo entry. There is a variant of || called || that will set the argument formula without any surrounding margin.
The "v3" position language makes excursions much simpler and more general.