These options affect how coding messages appear when building test scripts. Programmers can modify these settings and see the results in the overlay portion of the Editor screen. Best practices include using Consolas as the Font Family (it is easier to decipher the letter "O" and the number zero "0") and setting the viewing area to 30% so the language overlay does not put characters in the same space as the test script code characters.
Source: NETS User Manual, Revision D, document 132-06035-0006, section 3.11.2.