I am not seeing anything in the docs about the coding standard used in FreeRtos. I assume the prefixes are along the lines of 'u'=unsigned,'s'=signed (or short?),'p'=ptr ... so what is the 'x' and 'v' prefix supposed to mean?

See http://www.freertos.org/a00017.html#NamingConventions although this is a little old. 'x' is also used for variables of type portBASE_TYPE, which is the most efficient type for the architecture, typically char for 8bitters, short for 16bitters and long for 32bitters.

Regards.

'v' is also missing. v for void. So vTaskDelete() is defined in Task.c (from name) and returns a void.

Regards.