In this file are groups of substitutions, which UniRed makes automatically when you are typing. Every group have a title in brackets, after this are the substitutions: at left of the symbol = is a string, which must be recognized and substituted when you are typing, at right is a substitution string. Both strings can be quoted.
Non-ASCII characters are presented as in HTML, i.e. &#xxx; (where xxx is decimal number).
[HTML] <bl = <blockquote>
It means, if the substitution group named HTMLis switched on in the file settings, when you type <bl, you automatically receive <blockquote>