- models.AllowedFrontendURL: empty, or an absolute http(s) URL with a host and without whitespace, control characters, a double quote, <, > or & - classes.Rewrite leaves the document unchanged for a refused value, inserts through EscapeText/EscapeAttr and keeps a loc or href that would not stay an http(s) URL - TestRewriteUnsafeFrontendURL, TestAllowedFrontendURL and a stored-row check in TestSitemapImportSmoke