how to avoid this warning?

Recently,i am working with EPM570T10I,program with Verilog hdl.

When i compiler the code,but there is a warning in Quartus II:

Warning: Found 1 node(s) in clock paths which may be acting as ripple and/or gated clocks -- node(s) analyzed as buffer(s) resulting in clock skew.

Info: Detected ripple clock "flg_oc_1" as buffer

But,the signal "flg_oc_1" is not a clock in my design ,it is just a pulse signal。

How should i do to avoid the warning?

THX!!!