Notation for specifying the fractional part of a number

Question

Just like the title says, what is the notation for specifying the fractional part of a number?

Answer 1

The fractional part of a number $x$ is usually denoted by $\{x\}$ or $\operatorname{frac}(x)$ (see Wikipedia), i.e. $\{x\}=x-\lfloor x\rfloor$, where $\lfloor \cdot\rfloor$ is the floor function.

Answer 2

Braces is a common notation so the fractional part of $x$ would be denoted by $\{x\}$.

That being said, I would rather not use it without explaining it.