Mandatory command options not shown correctly

[andypiper]

mosquitto_pub and mosquitto_sub have a couple of options which are mandatory (-m and -t in the case of _pub, and -t for _sub)

These are not listed clearly in the command usage shown by default if no options are given, and curly braces are used to show them in the man pages which is not a standard way of showing mandatory options - curly braces are usually used to show options with a fixed set of possibilities. Required values are shown without braces.

[Roger Light (roger.light)]

Strictly speaking, mosquitto_sub has no mandatory arguments, although it might be worth changing it so that -t is mandatory. What do you think?