Sentence:  If the data for a URI component would conflict with the reserved purpose, then the conflicting data must be <WSD>escaped</WSD> before forming the URI. 
Meaning of the word marked with <WSD> tags:  To cause (a single character, or all such characters in a string) to be interpreted literally, instead of with any special meaning it would usually have in the same context, often by prefixing with another character.