SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
This code was storing references to patch entries which could move around in memory if a patch was erased from the middle of a vector or if the vector itself was reallocated. Instead, NewPatchDialog maintains a separate copy of the patch entries which are committed back to the patch if the user accepts the changes.