Manual for Version 3.1.
Instead of leading to page 234 (§ 17.5.2 "Basic Placement Options"), the links for the placement options left and right in the various examples (e.g. 1st example page 46) lead to /pgf/arrow keys/left and /pgf/arrow keys/right page 193 (§ 16.3.5 "Reversing, Halving, Swapping").
For the record: This was already the case for v3.0.1a (and I guess also in even earlier releases).
When I am not mistaken the hyperlinks are not set explicitly but by some automated stuff. This would explain the wrong destinations. There are other wrong hyperlinks as well, but I cannot remember them right now ...
I am not sure if this can be fixed (in an easy way).