Light contact involves just barely bringing your articulators (lips, tongue, teeth, roof of your mouth-- the oral mechanisms that make contact to form consonants for speech) together when you reach a stutter. It results in the phoneme sounding "softer" and sometimes it's harder to hear but it's better than going into a hard block. I have a friend who stutters and blocks on his /s/ sound, he uses light contact all the time and it gets him through it. Let me know if that helps! But if your stutter is undetectable or barely detectable by others, then maybe don't bother explaining it to people, if you're comfortable with it. Or maybe just try it once and maybe it'll bring your fluency up to 100%. I know for me, telling people before I give a speech just about doubles my fluency rate. Good luck brother.