Linguistic glosses typically abbreviate grammatical category labels, like this: Bản mẫu:Gcl, instead of the full name 'accusative'. The line containing such glosses is specified using |glossingN=yes (where N is the number of the line within the interlinear text). If no line is specified, then it is assumed such glosses are found in the second line (this can be bypassed with |glossing2=no). Within the lines so specified, any sequence of upper case letters will be interpreted as a grammar gloss and formatted in Bản mẫu:Small caps.

Additionally, the template will attempt to recognise the meaning of each abbreviation by looking it up in several places (more details below), and if the abbreviation is found, it will be formatted with a dotted underline and the "label" of this abbreviation will be displayed in a tooltip, like this: Bản mẫu:Gcl. Alternatively, the abbreviation can be turned into a link to the wikipedia article about the corresponding grammatical category, like this: Bản mẫu:Gcl. To choose the latter behvaiour, use the following parameter: |glossing=link. It is possible for separate lines to employ different styles, in this case the parameters used will be |glossing2=, |glossing3=, etc.

If a particular glossing abbreviation is to be treated differently from the rest, then {{gcl}} can be used:

{{interlinear|ngagun-yi nga-nanda-yi nung|{{gcl|1sg}}.NOM-{{gcl|ERG||}} {{gcl|1sgA|1st-person singular "agent"}}.3sgO-see-{{gcl|'''P'''ST}} {{gcl|3sg}}.ACC|'I saw him/her.'}}

In this example, {{gcl|acc}} marks up acc as a glossing abbreviation (it wouldn't have otherwise been interpreted as such because it is lower-case). {{gcl|1sgA|1st-person singular "agent"}} is used to define the meaning of the unusual abbreviation 1sgA, which wouldn't be recognised even in upper case. {{gcl|ERG}} displays the abbreviation as a link to the Wikipedia article. {{gcl|PST}} applies formatting to a part of a glossing abbreviation; if {{gcl}} weren't used here then the wikimarkup would have forced P to be treated as a separate abbreviation from ST.

If the grammatical category labels are not abbreviated but written out in full (like that: Bản mẫu:Gcl) then |glossing= should be set to no abbr, which will only apply small-caps formatting:

{{interlinear|glossing=no abbr|wǒ yǐjing jiàn-guò {Zhāng Sān} le.|I already see-EXPERIENTIAL {Zhang San} RESULTATIVE.|}}

Additional style[2] parameters can be applied to all gloss abbreviations using |glossing-style=. The default formatting using small caps can be disabled with |small-caps=no, and the default underlining can be turned off using |underline=no. To exempt a particular abbreviation from being treated as a grammatical gloss, use {{no gloss}}.

The pesky boxes with glossing messages that are shown in preview mode can be turned off with |display-messages=no.

Custom abbreviations

The template recognises some of the most commonly used abbreviations. However, it is recommended to always specify the meaning of each abbreviation used. There are several ways to do that:

• Defining at the article level. If an article uses a number of interlinearised examples and they share a set of abbreviations, then these can be defined once for the whole article using the following format:
• <section begin="list-of-glossing-abbreviations"/><div style="display:none;">
ABBR1:meaning1
ABBR2:meaning2
</div><section end="list-of-glossing-abbreviations"/>
  The list can contain any number of abbreviations; if a wikipedia article needs to be specified, it is added after a colon, for example: NEG:negator:Negation (linguistics). This whole code can be placed anywhere in the article, but it is customary to put it at the end, after the references but before any categories. It is visible only in edit mode, it is not displayed in the article.
• Defining at the level of a single instance of the template. This is done using |abbreviations= (or |ablist=). The list of custom abbreviations takes the same format as above: ABBREVIATION1:meaning1:wikipedia_article1; ABBREVIATION2:meaning2:wikipedia_article2... (specifying a Wikipedia article is optional and has no effect unless |glossing=link):

{{interlinear|abbreviations=RES:resultative; EXP:experiential aspect|wǒ yǐjing jiàn-guò {Zhāng Sān} le.|I already see-EXP {Zhang San} RES.|}}

• Defining a single instance of an abbreviation. This is done using {{gcl}}, as seen above
• Defining an abbreviation globally. This is done by the addition of an entry to the module's data page. The abbreviation will be recognised by any use of the templates, anywhere on the English wikipedia. This should be done only for completely unambiguous abbreviations.