99: Undeclared custom mark
An ampersand &
is used for custom marks in the text. A custom mark consists of the ampersand immediately followed by a small or capital letter, a
–z
or A
–Z
, or a single digit 0
–9
. The custom mark must be declared in a metadata declaration. In your case, it is not yet declared.
Solution
Make sure that you declare the custom mark. Note that its name is case-sensitive, so &a
and &A
are different marks. The following example demonstrates how &1
is declared to represent a HTML word break and how it is then used twice in a long word:
@ &1: ->,PHdicj4=
The patient suffers from sesqui&1pedalo&1phobia.
If you do not want to use a custom mark, but want a regular ampersand instead, you can prepend a backslash: \&