Place this directly under the second-level language heading (such as ==Spanish==) in an entry to add this to the language's appropriate phrasebook category. The template must be accompanied by a parameter with a the appropriate language code as well (e.g. {{phrasebook|es}}
for the Spanish phrasebook). An optional final parameter can add it to a subset of a phrasebook (e.g. {{phrasebook|es|Communication}}
will categorize an entry in Category:Spanish phrasebook/Communication).