--- title: prolog.data description: "## Syntax **prolog.data**(**data**((**name**=namevalue)(**value**=datavalue))) namevalue name of data parameter being added datavalue value for data parameter being added ## Purpose The prolog.data() annotation is used to add information to the prolog of a topic. This can be anything from a simple…" url: "https://www.stilo.com/docs/migrate/prolog/prolog-data/" updated: "2021-04-27" category: Annotations / Prolog tags: - Annotations --- # prolog.data ## Syntax **prolog.data**(**data**((**name**=namevalue)(**value**=datavalue))) namevalue name of data parameter being added datavalue value for data parameter being added ## Purpose The prolog.data() annotation is used to add information to the prolog of a topic. This can be anything from a simple text tag and value to an *href* to content located elsewhere to a complex nested structure of *data* elements. The following is an example of some text from your source document that you want to put into*prolog.data()*. [![Source document text](https://www.stilo.com/wp-content/uploads/2021/03/prolog-data-source-document.png)](https://www.stilo.com/wp-content/uploads/2021/03/prolog-data-source-document.png) The following is an example of what the annotation may look like when filled out. [![Rule for prolog.data()](https://www.stilo.com/wp-content/uploads/2021/03/prolog-data-rule.png)](https://www.stilo.com/wp-content/uploads/2021/03/prolog-data-rule.png) The following is an example of the DITA output you would get from this annotation. ``` ```