This website contains links to software which is either no longer maintained or will be supported only until the end of 2019 (CKFinder 2). For the latest documentation about current CKSource projects, including software like CKEditor 4/CKEditor 5, CKFinder 3, Cloud Services, Letters, Accessibility Checker, please visit the new documentation website.
If you look for an information about very old versions of CKEditor, FCKeditor and CKFinder check also the CKEditor forum, which was closed in 2015. If not, please head to StackOverflow for support.
This doesn't seem to work in FCKEditor v2.6.3 for relative links that don't start with "/". E.g.:
<base href="mysite.com/">
<img src="/images/test.jpg">: shows up in editor as it should
<img src="images/test.jpg">: doesn't show up in editor, but it should!