National Instruments NI 2590/2591 - Manual (Page 6)

Conventions
The following conventions are used in this manual:
<> Angle brackets that contain numbers separated by an ellipsis represent a
range of values associated with a bit or signal name—for example,
DBIO<3..0>.
This icon denotes a note, which alerts you to important information.
This icon denotes a caution, which advises you of precautions to take to
avoid injury, data loss, or a system crash.
This icon denotes a warning, which advises you of precautions to take to
avoid being electrically shocked.
italic Italic text denotes variables, emphasis, a cross reference, or an introduction
to a key concept. This font also denotes text that is a placeholder for a word
or value that you must supply.
monospace Text in this font denotes text or characters that you should enter from the
keyboard, sections of code, programming examples, and syntax examples.
This font is also used for the proper names of disk drives, paths, directories,
programs, subprograms, subroutines, device names, functions, operations,
variables, filenames and extensions, and code excerpts.