guide·line 
/ˈgaɪdˌlaɪn/ noun
plural guide·lines /ˈgaɪdˌlaɪn/ noun [count] : a rule or instruction that shows or tells how something should be done — usually plural ▪ The government has issued new guidelines for following a healthy and balanced diet. ▪ calling for stricter guidelines ▪ Here are some basic guidelines for helping you choose a dishwasher.
