When establishing a relative symbolic link, what does the "different versioned object base" error mean?

I am attempting to create a relative symbolic link via clearcase as so: ct ln ../../../some/actual/file.txt file.txt

However, I get the following error:

cleartool: Error: Source "../../../some/actual/file.txt" and destination "file.txt" are in different versioned object bases.

In context of clearcase relative symbolic links, what does "different versioned object bases" mean?

Solution

First "in different versioned object bases" refers to VOBs, two different permanent data repositories in which you store files, directories, and metadata.

A cleartool ln without the -slink option would create a hardlink, that is an additional name for an existing element.

And:

For VOB hard links, each pname must specify an existing element that is not a VOB symbolic link and that resides in the same VOB as the link being created.
For VOB symbolic links, pname need not reside in the same VOB as the link to it, nor be an existing element.