The dependency management docs are missing a mention of the available import_mappings feature. The docs should explain the reasons to use the feature, how to apply it, and what to expect in the mappings.

• You don't need to declare any ECS fields used in the integration.
• The generated component templates for all data streams within the package will include dynamic mappings for ECS fields. It's an all or nothing feature that cannot be controlled per data stream.
• The dynamic mapping source lives in elastic/elastic-package and IS NOT tied into the ECS version specified in build.yml. (IIUC?) Include a link to the source file for reference.
• Currently the index.query.default_field setting will not include ECS fields defined through dynamic mappings. Only fields statically declared in the data stream will be added the the default_field list. This means that searches without an explicit field name specified will not query against ECS fields.
• ECS fields mapped through dynamic mapping will not be included in the field list in the package README.

Some rational and history on the import_mappings feature can be found in elastic/integrations#7273 (comment).

https://github.com/elastic/elastic-package/blob/60ee15405bfc1f759b745deffc56b7c2d33bdebe/docs/howto/dependency_management.md

https://github.com/elastic/package-spec/blob/037631bddaffe6519b61eb41c186fb929675d6e1/spec/integration/_dev/build/build.spec.yml#L23-L26