Possession with the Intent To Deliver (PWID) is defined three ways in Pennsylvania: 1. Selling; 2. Sharing; 3. Quantity.
Selling narcotics is obvious, possession with the intent to deliver in that you hold narcotics that you intend not to use, but to deliver to other people. The packaging of the narcotics is not necessarily relevant if the sale is observed. Be it marijuana, cocaine, pcp, heroin, or methamphetamine, this type of PWID is easy to understand.
Sharing narcotics is a bit more tricky because people in the general public think of PWID as drug dealing, so when someone goes to a party and brings a enough marijuana or cocaine for the whole party, they are not a drug dealer, just a generous party goer. However, this too meets the plain language definition of Possession with the Intent to Deliver because the person possessed the narcotics and delivered them to other people.
The third example of possession with the intent to delver is the most difficult for people to understand, and that is quantity. The basis for this type is that a reasonable could not personally ingest the amount possessed alone, therefore they must possess it with the intent to deliver. This type of PWID is often the most defensible from my perspective because based on the packaging, the weight, or the circumstance surrounding the arrest, the quantity can often be explained away in a very reasonable manner that is quite convincing to the trier of fact.