Hi Andrew, some of the regex quantifiers used in Selenium Webdriver are:
- 
* : “match anything”
 
- 
[ ] : “match any single character found inside the square brackets”
 
- 
[aeiou] : "matches any lowercase vowel"
 
- 
[0-9]: "matches any digit"
 
- 
[a-zA-Z0-9] : "matches any alphanumeric character "