I am looking for Unix command syntax conventions to describe the use the following : (may be we do not have all the conventions below ) 1- boldface 2- italics Italic text indicates what ? 3- [x] Square brackets indicate what ? 4- {x} Braces ? 5- (x) paranthesis ? 6- y | z vertical lines indicate what ? There is no comprehensive details in the link below: http://cm.bell-labs.com/cm/cs/who/dmr/manintro.html

boldface is the name of the actual command you are executing
italics or underline indicates mandatory arguments
square brackets indicate optional arguments
a vertical bar indicates two mutually exclusive options

I've never seen parentheses or curly braces used.

Thanks for that ,,,could you please send any resources on net for future reference.