The document provides guidelines for commenting on blog posts in 3 or fewer sentences. It advises readers to read the post twice to understand it, read other comments to potentially comment on them as well, remember the "Grandmother Rule" to be respectful, use only usernames to maintain privacy, make a point and support it with evidence or explanation using the "PEE" structure, and draft comments elsewhere first before posting. It also suggests using proper English in at least 3-5 sentences, checking back later, and thinking carefully before submitting.