What does deactivating the validations do for parsing a rss field?

Hello!
I am trying to use this gem to parse RSS feeds. However, many RSS feeds have some data that throws an error such as #<RSS::MissingTagError: tag <link> is missing in tag <image>>. On such rss feed is https://feeds.megaphone.fm/GLT1412515089. Disabling validation fixes those errors (calling RSS::Parser.parse(body, false).
I could not find any documentation for what disabling the validations for parsing actually does. Intuition tells me that it most likely disables validations like the date having a certain format, or some tags existing within other tags, such as the error just shared.
So my question is, what does disabling validations actually do? And is parsing with disabled validations as safe (from a security perpective) as parsing with validations enabled?
Thank you!

Start at the RSS::Parser.parse(body, false) entry point and compare it with parsing the linked feed using validation enabled. Trace which checks the flag changes and document the behavior, including what the issue's security question can be answered from the implementation. Done means the validation behavior and safety implications are explained in the gem's documentation.