@Section
    @Title { Labelled (as opposed to numbered) references }
    @RunningTitle { Labelled references }
    @Tag { labelled }
@Begin
@PP
Lout ordinarily assigns a number to each reference, and prints this
references. @RawIndex { references }
references.labelled @SubIndex { labelled }
labelled.references @Index { labelled references }
number beside the reference in the reference list and at the point(s)
of citation.  There is a way to make Lout use a label of your choice
instead of a number for each reference.  First change the following
setup file options to the values shown (these options are explained
in Section {@NumberOf changeref}):
@ID @OneRow @Code @Verbatim {
@RefCiteLabels { @Label }
@RefListLabels { @Label. }
@RefListLabelWidth { 4.00f }
@RefListSortKey { @Label }
}
Then make sure that every reference you cite has a {@Code "@Label"} option:
references. @RawIndex { references }
references.label @SubIndex { @Code "@Label" }
label.references @Index { @Code "@Label" (references) }
@ID @OneRow @Code @Verbatim {
{ @Reference
    @Tag { kingston1995lout.expert }
    @Type { TechReport }
    @Label { Kin94 }
    ...
}
}
@Code "@Label" may contain several words, and even font changes, but not
an arbitrary object.
@PP
The effect of these changes is that your references will now be labelled
with their @Code "@Label" options instead of with numbers, and they will
be sorted by label instead of by tag.  However, tags are still used when
citing.
@PP
The big problem with labels is that they vary from document to
document, either because of a change of style or because the usual
first few letters of the authors' names plus year has to be augmented
with {@Code a}, {@Code b}, {@Code c} etc. to distinguish publications
by the same authors in the same year.  To help you overcome these
problems, the @Code "$" symbol has a @Code "label" option:
@ID @Code {
"@Cite { $ label { Kin94a } kingston1995lout.expert, ... }"
}
The @Code "@Ref" and @Code "@ChapRef" symbols also have a @Code label
option.  If you use this option, it will be used to label the reference
instead of the @Code "@Label" option from the @Code "@Reference" symbol
(indeed, the @Code "@Reference" symbol need have no @Code "@Label" option
in this case).  But note that using @Code "label" does not itself give
you labelled references; you get them with the setup file options as
explained above.
@PP
If your labels turn out to be too wide for the space allowed for them
in the reference list, you have two alternatives.  One is to increase
the @Code "@RefListLabelWidth" setup file option shown above, since it
determines this space.  The other is to change the @Code "@RefListFormat"
setup file option to {@Code "DropLabels"}, which produces drop items:
@ID @OneRow {
@RawTaggedList
@DTI { Kin94a. } @RefPrint kingston1995lout.expert
@RawEndList
}
Then it won't matter how wide your labels are.
@End @Section