@IRISH791 mentioned several of the criteria and, FWIW, here is the rest of the USPS "Drug-Package Profile". This has been around since the 80's in one form or the other. There is a lot of latitude in the interpretation of the profile both when they apply for a warrant to search and when/if it goes to court.
1. Are of a
particular size and/or
shape.
2. Are heavily taped so that all openings are sealed.
3. Bear hand-written labels.
4. Bear
unusual return names and addresses.
5. Emit unusual odors.
6. Bear fictitious return addressees.
7. Are sent to
particular destinations
also this to consider when checking the USPS database to find out "Where is my package"?
"According to the website Ars, a federal drug investigation reveals how the United States Postal Service’s (USPS) law enforcement unit can use IP logs on the postal tracking website to investigate crimes
“The USPS database reflected that an individual using a computer or other device with IP address 75.67.6.214 accessed the USPS Track ‘n Confirm website to follow the progress of both the Florida Parcel and Bates Parcel #1,”Dowd wrote.
“What’s most bizarre about this, is the case was tipped off by an algorithm, a system that mines Track N’ Confirm user-data in order to detect suspicious activity, has triggered the investigation,” Ghappour told Ars in an interview."