Topic: What is a "Line Clear" in Tetris 99?

I ask the above question because the daily missions often say you need to complete a certain number of line clears in order to get a ticket. I would think that a line clear would simply be every time you clear a line, but apparently this is not the case because it isn't getting me the tickets. Does anyone know what Tetris 99 considers to be a "line clear"?

Does it mention an specific game mode?

@JDORS If it's not a single line then it must be 4 lines, otherwise known as a Tetris. If I remember correctly the challenge requires you to get 10 line clears to earn a ticket. On the menu screen it tells you near the top how much you've achieved so far.

I highly recommend unlocking the Zelda theme, the background and Zelda theme remix look and sound superb. I'm undecided whether to go for Mario or DK theme next, I'm thinking DK. I have 4 tickets just now but I'll play tonight for another 2.

Maybe it is 4 lines then. Thanks. I've already unlocked the Mario theme and I absolutely love it!