This convention or term

Is used to indicate this

this type style

text that you type
filenames and directory names
onscreen messages

italic

document titles
variables
emphasis

square brackets ( [ ] )

optional items in a command
For example, [ true | false ]. (Do not type the brackets.)

pipe ( | )

a choice between items in a command or parameter. When enclosed in braces ( { } ), the choice is mandatory.

UPPERCASE

DMSII data set and data item names

MCP server
host
mainframe (terms)

Unisys ClearPath NX, LX or A Series mainframe

DBEnterprise (term)

DATABridge Enterprise Server

DBServer (term)

DATABridge Server