The exact details on how to submit changes for merging depends, of course, on the development workflow that the project is using. Various classes of possible workflows are described in Chapter 5, Collaborative Development with Git.
If the project has a dedicated maintainer or, at least, if it has someone responsible to merge the proposed changes into the official version, you would need also to describe submitted changes as a whole (in addition to describing each commit in the series). This can be done in the form of a cover letter for the patch series while sending changes as patches via e-mail; or it can be comments in the pull request while using collocated contributor repositories model; ...
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