Rodney "Rod" Belding was Richard Belding's younger brother who only appeared in one episode of the series.
Apparently Rod was the more popular of the two brothers with his laid back personality and understanding of people.
However he seemed to have a habit of getting people's hopes up, making promises he couldn't keep and letting people down. When his brother Richard (whom he nicknamed "Ritchie") invited him to take over for a teacher at his school Rod promised him that his attitude had changed.
Being at Bayside
When Rod took over as a substitute teacher for a history class, he became instantly popular with the students especially Zack Morris when he made them tear up the hard mid-term their previous teacher had given them and gave them the grade that they thought they deserved.
When he, Zack and Screech were watching a Dodger's game, he promised an experience of white water river rafting for the class trip instead of the camping trip in the Yosemite mountains that his brother had planned.
During class, they went to the gymnasium to practice for their trip. Mr. Belding walked in while Rod was showing Zack and Slater how to give CPR to Kelly and Jessie and made everyone go back to class.
Zack was angry and told Mr. Belding that he was just jealous of his own brother.
The students then prepare for the trip but Rod then tells his brother in his office that he won't be taking them as he has made plans to spend the weekend with a stewardess named Inga that he had just met and asks Mr. Belding to come up with an excuse for him.
Mr. Belding is angry and disappointed with his brother for these actions after promising him that he had changed and throws him out.
Rod walks out, presumably not noticing that Zack was outside and had heard everything.
Mr. Belding takes charge, tells the students that Rod couldn't be there and he would be taking his place for the trip. When the other students leave, Zack asks him why he didn't tell the students the truth about Rod abandoning the trip for his date with the stewardess. He admits he overheard his conversation with Rod when he came to the office and learned his true nature. Mr. Belding understands how angry Zack is with Rod, but he didn't want to cancel the trip and let his fellow students down. In turn, Zack apologises for his behaviour and admits that Rod may have been more exciting but they have their principal as the better Belding.