Sentence:  Although it is not recommended that you <WSD>wet sand</WSD> color coats, you might be able to lightly sand off nibs, providing you are prepared to touch up the spots with a light color coat. 
Meaning of the word marked with <WSD> tags:  To sand using extremely fine-grained sandpaper, using a lubricant such as water or oil to prevent the sandpaper from clogging.