onsemi is a well-regarded supplier of semiconductor components, including a wide selection of SMT diodes. Most of these devices list a two-digit ‘Device Code’ in their documentation, such as PD for BSS84LT1G or SP for BSS84. We’ve been receiving a number of questions lately on what these device codes call out and how they affect the product’s specifications.
In short: they don’t. The device code is an identifier for the product, as the full part number is usually too large to fit legibly on these small case size products. They have no significance for the part’s specs beyond identifying the part upon receipt.