Some discontinued library mentions the MIT license only in their readme:
Do license mentions in
README file without actual
LICENSE file mean same in court?
Yes, it's OK to not have any license file.
Without any license, the default is that all rights are reserved. If someone other than the author wants to use this code, they have the obligation of obtaining a valid license.
For open source projects, there are a variety of conventions to unambiguously indicate licenses. For example:
SPDX-License-Identifier headers or package manager metadata
If an author follows one or more of these conventions, it is likely that a court will find that the author intended to issue the license. Special files such as a
LICENSE do not have magic legal power, they are just one industry convention among many.
However, things become difficult if there is conflicting information, and the linked project is an example:
In the README, it is said that
FCAlertView is available under the MIT license. See the LICENSE file for more info.
However, no LICENSE file exists.
In the source code files, we instead find “all rights reserved” copyright headers without any mention of an MIT license
Copyright © 2016 <the author>. All rights reserved.
The project in general also suggests that the author is not very experienced, so they might not fully understand the consequence of issuing an MIT license for their code.
So while there are indications that the software is available under the MIT license, there are also indications to the contrary. It would therefore be unwise to use the code without obtaining clarification about the licensing status from the author.