The list of ideas suggests plausible GSoC projects that a GSoC contributor
will work on during the coding period if they are selected.And a PR isn't "sent with"
the application but rather mentioned in it; it is the work you do with the organization
before the GSoC period. It can be a patch that fixes an existing bug, or an
addition of a well-discussed feature, a feature enhancement, or some contribution
along those lines. The purpose behind this rule is so that the mentors can have
an assurance that the applying contributor has had some prior experience working
on the codebase.