Documentation Tools: Where is the metadata from source doc pages used?

Question

I am experimenting with the Documentation Tools for the first time, to integrate my package's doc pages into the Documentation Center. Doc pages are generated from a "source notebook" that the Workbench sets up. It looks like as below, after filling out only a few sections.

It looks like the top section contains fields for entering metadata. Where is this metadata used? What can I do with it? Does it show up in the Documentation Center in any way or does it interact with my package?

I am interested in the following in particular: New in, Modified in, Keywords, Syntax Templates.

Answer 1

This is a partial answer. The documentation tools palette has a button at the top which opens a sample function page:

This sample page has some notes about what these sections are for:

The Keywords section can be list of words. Each must appear in a separate cell. Searching for these words in the Documentation Center will find the page, even if the words don't otherwise appear in the page.

I do not know if any of the other sections have any practical effect when compiling the documentation, though it's clear that they can hold information that is useful when working in a large team.

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Some of the metadata will be written into the built documentation notebook as TaggingRules, and can be retrived with this command, evaluated in that notebook:

CurrentValue[EvaluationNotebook[], {TaggingRules, "Metadata"}]

Try this on any documentation page. E.g. on the Dataset page it returns

{"built" -> "{2016, 9, 21, 21, 21, 30.299152}", 
 "history" -> {"10", "", "", ""}, "context" -> "System`", 
 "keywords" -> {"data set", "database", "SQL", "noSQL", "MongoDB", 
   "hierarchical data", "big data", "ORM", "object relational model", 
   "dataframe", "data frame", "pandas", "data model", "data query", 
   "select from", "data cube", "OLAP cube", "data tensor", 
   "data container", "structured data"}, "specialkeywords" -> {}, 
 "tutorialcollectionlinks" -> {}, "index" -> True, 
 "label" -> "Built-in Wolfram Language Symbol", "language" -> "en", 
 "paclet" -> "Mathematica", "status" -> "None", 
 "summary" -> 
  "Dataset[data] represents a structured dataset based on a hierarchy of lists and associations.", "synonyms" -> {}, "tabletags" -> {}, 
 "title" -> "Dataset", "titlemodifier" -> "", 
 "windowtitle" -> "Dataset", "type" -> "Symbol", 
 "uri" -> "ref/Dataset"}