Big Mess o’ Wires has a review of Verilog warnings:
Those of you who’ve followed the blog for a while know about my many frustrations with Verilog. Because it feels sort of a like a procedural programming language, but very definitely isn’t one, I keep expecting to be far more competent at Verilog design than I actually am. While working on Plus Too, the Xilinx synthesis tool reported many, many warnings that I didn’t understand. The warning list grew to at least 100, and was so long that I just stopped reading it. That was dangerous, as most of the warnings were likely problems that needed to be addressed.