What are the differences between SIGUSR1 and USR1

Are there any differences between SIGUSR1 vs USR1 when it comes to killing a process

kill -SIGUSR1 {pid}

or

kill -USR1 {pid}

Solution 1:

There is no difference (apart from the number of characters you have to type).

Citing e.g. https://man7.org/linux/man-pages/man1/kill.1@@procps-ng.html

Alternate signals may be specified in three ways: -9, -SIGKILL or -KILL.

Not all variants of the manual page contain this explanation.