Enabling prioritization

[dlavelle]

For the Milestone Overview link in testlink desktop (you only see it as admin or admin of a Test Plan.) The comments in the code says :
Define urgency of a Test Suite.
It requires “priorization” feature enables.

How do I enable this feature?

[fman]

on test project creation

[georgemrc]

Has this been disabled on 1.9.17? I remember having seen it active (at some point), but now that I want to use it I can't seem to get it enabled.