Primary US Classification with Children Field (PSCLS)
To both query patents by their primary US classification and include all children classes in a single query, use the PSCLS field code. The PSCLS field code gives you fine-tuned control over your class queries.
- PSCLS:705/50 --> Displays all documents in ANY of the "Cryptography" classes listed above.
- PSCLS:705/60 --> Displays, in one query, all cryptography patents and applications specifically for the "postage metering" classification. In other words, note the two children classes (61 and 62) that are represented by the "two dot" heirarchy structure. Documents in these two children classes are included.