All should read this post, to help understand what technical analysis is all about. This answer ended up going beyond your question.
--------------------------------------------
I did answer that but, yes, candle bodies closes gaps, not wicks. This subject, as with all charting, can't be considered correct or wrong though. As there is no one single god dictating black & white rules.
My interpretation is from experience of watch gaps for 10 years. Because I've seen to many gaps which have wick fills, still be re-visited with candle bodies later. And this happened more the 50% of the time, so I teach and personally require candle body fills to satisfy a close.
The thought process and theory is based on emotion causes gaps in price, emotion can satisfy them. You need the masses to say the gap was uncalled for. Not just another emotion surge.
At any rate, using candle bodies actually is safer, but I wouldn't argue the subject, with any other technical analyst. I'd just do things my way, because of my experience. Others can do things there way. All charting is not black and white. Neither is this. It's an art form, seen in the eye of the chartist/artist.
Every Rule of Thumb, TIP and non book chart pattern, I post about is seen in my mind, using my experience. Adding to what I've learned from standard practices. And backed up by repetitive observations. It's some one noticing repetition in chart, which caused the first chart pattern to be taught. I just add to the excepted standards found in books, with my personal experiences. IMO every good analyst should try to improve their knowledge. And continue past what they learn in books, using experience. I happen to pass it on. But I'm sure every technical analyst uses their own special observations.
The more you see something happen, the more you can rely on it ! Is basically "charting" or analysis and how I teach one to always look for new things, to aid with decision making.
Charting and technical indicators together become technical analysis. Charting is a art from, finding patterns in price movement and indicators are mathematical calculations explaining charting patterns. Together they aid with entry or exit decisions, based on historical price movement, by projecting future price action.
Some analyst see shares of gray. I try to see 256 colors, by reading the sentiment and phycology behind the gray.
