Include licensing and copyright info in source code files
Especially if the code is expected to be copied elsewhere, it would make sense to explicitly state the license (and copyright holder) in the header of each source code file.
Some short and well explained and very easy to implement best practices can be found here:
I am talking about something as small as this (not a huge wall of text):
# © 2018 Tildes contributors <https//tildes.net> # # SPDX-License-Identifier: AGPL-3.0-or-later
# Copyright 2018 Tildes contributors <email@example.com> # # SPDX-License-Identifier: AGPL-3.0-or-later
or some variation of this. Note that you only need to provide only one way to indicate copyright (word or copyright sign) and which contact information is more useful (homepage or e-mail) is entirely up to the project.