I was finding test points in a schematic of an Analog Devices Evaluation board. In one of the schematic pages, there is a clause mentioned "do not populate test points".
Does anyone knows what it means ?
Yes, it means they are points provided for testing purposes so do not connect components etc to those points.
Test points are very useful during development. A test point can be a flat SMT pad, or a throughole pad. Sometimes, a test point has a loop for clipping a probe onto (throughole examples, SMT examples). Sometimes, these loops are used only during R&D testing. In mass production the test points are contacted by automated test equipment, and the loops aren't installed in production to save cost.