Short and descriptive. People read web addresses in search results and shared links, and a slug like /coffee-montreal tells them what to expect. Three to six words is plenty.

Hyphens, not underscores, for web pages. Google treats a hyphen as a space between words, while an underscore joins them into one long word. Underscores are fine for file names and code.

Plain letters travel best. Accented and non-Latin letters work in modern browsers, but they turn into long strings of %-codes when copied into emails or older software. "Plain letters only" swaps them for their closest English letters, including Cyrillic and Greek.

Don't change a slug after publishing unless you set up a redirect, or every existing link to the page will break. Everything runs in your browser.