The notation is not the problem when it comes to cancels, it’s the timing.
A cancel is also known as a 2 in 1 and is defined as the product of canceling the recovery of a move into the start of another move. In the case of marvel vs capcom 3, that means you cancel the recovery portion of a normal or special into another normal, special or super.
For example, if you do standing h with iron man and then uni beam slowly, you get the blast from h, then iron man puts away his palm lasers, and then fires off a uni beam with his chest.
When you use a 2 in 1 or cancel, you do s.h and immediately input d, df, f + atk and you get iron man shooting out his palm lasers and before he even puts his hands down, he begins shooting with his chest laser and you get a combo. What happened was you canceled the recovery of the standing h (the portion of the move where he puts his hands down) and goes straight into the unibeam.
There is no notation difference in the combo of s.h xx unibeam. you just have to input the unibeam very quickly right after the s.h hits.
whenever they say S xx unibeam, xx denotes cancel
if it was s, unibeam, the “,” would denote a link where you let the move finish completely and then just hit them with the new move after the previous one recovered. An example of this is when you do s, super jump cancel, air m, air m, air h, air d+h, land, s. The d+h, s is a link where there was enough hit stun in the air to continue the combo on the ground upon landing.
To address the fly topic again, I think people look for the wrong thing when it comes to flying. They just assume that the only thing that really matters about a fly is how fast you fly around and how long the fly lasts when in actuality, the really important thing is how long it takes before you can hit somebody after you’ve begun flying.
For example, Iron Man can hit you on frame 14 after you cancel d+h into fly (d+h xx fly), meaning he has a ton of time to link whatever the hell he wants after he?s begun flight. Other characters do not have this luxury and have a much more difficult time hitting you after they?ve begun flying.
For example, sentinel air h xx fly, air l is very difficult in comparison to aerial rave s, air m, air m, air h, air d+h xx fly, m/h/d+h/u+h because his flight is slower. The only reason you can do sentinel?s fly combo is cause air h has massive hit stun. You reel for a damn hour and a half sometimes from that move so you cancel it late and visually hit confirm. Doom combos, storm combos, etc. are much more difficult than iron man combos once you realize that IM flight is godlike because he?s probably the most nimble air character in the game with 3 directional h?s, a double jump, air dash, flight and 2 air specials. Storm has similar aerial rave potential, but it?s much more difficult to pull off.