Excerpt from the man page:
--- cut ---
BUGS
[...]
If two or more files have the same name in different main directories (tree and seer below) but the same subdirectories they will collide. The first one located will be linked the second one ignored.
Example: /app/tree-1.0/bin/house
: /app/seer-1.0/bin/house
--- cut ---.
2003-06-07 18:33:54 UTC in relink