Journals have access to the identifying information an author provides when submitting the manuscript (name, email, title, and institution), as well as any data the author provides via uploaded files (e.g. manuscript text, supporting files, cover letter, etc.).
The only other information that can be collected is the optional demographic information that some journals allow authors to submit. Authors are NOT required to enter optional demographic data (e.g. gender, race, etc.) when submitting a manuscript. If an author chooses to submit to a journal that allows authors to submit demographic information, the submission form will include an optional section to submit this type of information. The section will clearly delineate which journals are allowing you to submit this information. This information will only be shown to journals configured to allow authors to submit demographic information at the time the author submits the manuscript.
To learn more about being an author, check out our Author Guide.