Don't unescape anything at all.

Don't unescape anything special, but all normal unescaping will happen. This is a placeholder and can't be combined with other flags (since it's just the absence of them). All other unescape rules imply "normal" in addition to their special meaning. Things like escaped letters, digits, and most symbols will get unescaped with this mode.

Convert %20 to spaces. In some places where we're showing URLs, we may want this. In places where the URL may be copied and pasted out, then you wouldn't want this since it might not be interpreted in one piece by other applications.

Unescapes '/' and '\\'. If these characters were unescaped, the resulting URL won't be the same as the source one. Moreover, they are dangerous to unescape in strings that will be used as file paths or names. This value should only be used when slashes don't have special meaning, like data URLs.

Unescapes various characters that will change the meaning of URLs, including '%', '+', '&', '#'. Does not unescape path separators. If these characters were unescaped, the resulting URL won't be the same as the source one. This flag is used when generating final output like filenames for URLs where we won't be interpreting as a URL and want to do as much unescaping as possible.

URL queries use "+" for space. This flag controls that replacement.