LC0017

LC0017 - Write to FlowFields should be explained by a comment

if you write by accident into a flowfield because you did not check the fieldclass, runtime errors can appear.
To prevent this, this rule will raise a warning. If you actually intent to write to a flowfield, just add a comment with a short explaination about the why. This will help others, who read the code later, to understand what you did there.