This chapter is mainly based on the exploring the various ways in which fonts are demonstrated at point of sale. When searching for that perfect typeface to use in a current project you are often faced with and endless list that repeats the same phrase time and time again a good example would be ' The quick brown fox jumps over the lazy dog'. This phrase is a pangram and has been used for years and years simply because it is one that will allow a person to see what each letter in the alphabet will look like in that particular font. Of course it isn't the only phrase that includes all the letters of the alphabet others that have been used in the past include that created by Hermann Zapf 'Typography is known for two-dimensional architecture and requires extra zeal within every job' which in my opinion is rather suited even though it's quite long. I think pangrams are good as not only do the demonstrate each letter but it also put the font into some sort of context instead of simply writing out ABCD etc.
Another common phrase used is the actual name of the specific font, this is what you are likely to see whilst browsing on dafont or linotype which doesn't really show you all the letters at first glance, but like with most other sites once you click on them you are often able to type in your own sample text and there is usually a display of all the other characters in the font or further examples of the sample text in various point sizes and weights.
Adjectives or nouns that relate to the fonts appearance are sometimes used as sample text I can see why it could be useful for some people as if they are looking for a font particular style perhaps something similar to a western style font so the display text could be something like cowboy or ranch etc. or if a font looks similar to a particular logo type like the coca cola or Facebook these phrases may be used as the sample text for the font. The negative side of this is that it may contribute to limiting the typefaces versatility in the viewers mind.
Sources & Related Info
Book: Just My type by Simon Garfield, 2010 version, chapter 14, ISBN 978-1846683022