In Troika! the numinous edition in chapter 11 Getting Better the rules suggest a tick next to the advanced skill on every successful skill roll (roll under) on the character sheet. After rolling for advancement of 3 skills (roll over) the rules state that all ticks have to be removed from the character sheets.
But what are ticks used for? How is the count of ticks relevant?
Update: Here is the page from the book.