Symbol for kernel and range of a linear transformation

Question

I'm wondering what symbol is used for the kernel and the range of a linear transformation. I've seen them being written as such:

$\ker(T)$

$\mathcal{R}(T)$

Are these the "correct" symbols for the kernel and range, or do they differ between different mathematicians? Are there any that are used more frequently? This is being a bit pedantic, but I'm just curious.

Answer 1

Daniel Fisher gave a good comment which I'm putting here:

Both of the notations are correct, but usually those two are not used together because of consistency. Here are the "pairs" that are usually used together for the kernel and the range:

$\ker T$ and $\operatorname{im} T$

$\mathcal{N}(T)$ and $\mathcal{R}(T)$