Tektronix AWG710 Programmer's Manual page 38

Command Syntax
General Rules
2-8
Here are three general rules for using SCPI commands, queries, and parameters:
H You can use single (' ') or double (" ") quotation marks for quoted strings,
but you cannot use both types of quotation marks for the same string.
correct: "This string uses quotation marks correctly."
correct: 'This string also uses quotation marks correctly.'
incorrect: "This string does not use quotation marks correctly.'
H You can use upper case, lower case, or a mixture of both cases for all
commands, queries, and parameters.
:OUTPUT:FILTER:LPASS:FREQUENCY 200MHZ
is the same as
output:filter:lpass:frequency 200MHz
and
OUTPUT:filter:LPASS:frequency 200MHz
NOTE. Literal strings (quoted) are case sensitive. For example: file names.
H No embedded spaces are allowed between or within nodes.
OUTPUT:FILTER:LPASS:FREQUENCY 200MHZ
correct:
OUTPUT: FILTER: LPASS:FREQUENCY 200MHZ
incorrect:
AWG710 Arbitrary Waveform Generator Programmer Manual