The term 'OLD SODA BRAND' can be solved by the four-letter word 'NEHI'. NEHI is a brand of soft drink that was first introduced in 1924 by Chero-Cola/Union Bottle Works. It was originally sold in the southeastern United States, but eventually expanded to become a national brand. The name NEHI comes from the phonetic spelling of the phrase 'knee-high', which was used to describe the bottles it was sold in.