### Key Terms and Concepts

ADIF (Amateur Data Interchange Format) -- A log file format that many logging applications can export that describes one or more QSOs. It is not necessary to view or modify ADIF files in order to use TQSL , but for more information, see http://adif.org.uk .

Cabrillo -- A log file format used for the submission of contest logs that describes one or more QSOs. It is not necessary to view or modify Cabrillo files in order to use TQSL , but for more information, see http://www.kkn.net/~trey/cabrillo .

Callsign Certificate -- A unique file issued to a user by the ARRL in response to a request generated by the TQSL application that is used to digitally sign a log file, thereby confirming its authenticity. TQSL also enables you to view your Callsign Certificates and renew them before they expire.

Digital Signature -- A cryptographic means of enabling a sender to convey information to a receiver in a manner that assures the receiver that

- the information comes from the sender
- the information has not been subsequently modified

| LoTW users can employ the TQSL application to generate a digitally signed log file containing their QSOs for submission to LoTW, or they can use one of the many logging applications with this capability.

Log File -- A file containing QSO records in either ADIF or Cabrillo format. A Digitally Signed Log File has been digitally signed by TQSL and can be submitted to LoTW.

LoTW Account -- the web page from which an LoTW user can

- view the results of LoTW's processing of a digitally signed log file submitted to LoTW
- view the status of each of your Callsign Certificates
- view QSOs that have been submitted to and accepted by LoTW
- view QSOs that have been confirmed by LoTW
- view DXCC, VUCC, WAS, and WPX Award Credit
- submit QSOs confirmed via LoTW for additional DXCC, VUCC, WAS, and WPX Award Credit

The username and password needed to log in to your LoTW Account are specified in the email message from the ARRL that conveys your first Callsign Certificate.

Mode Group -- a collection of similar modes. The Phone mode group, for example, includes the modes AM, FM, and SSB. Other mode groups include CW, Data, and Image. Mode groups are defined in TQSL's Configuration Data.

Station Location -- a collection of information specifying an operating location and optionally a Callsign Certificate. Station Locations can be created, modified, and deleted with TQSL. A Station Location specifies the following geographic information:

- a DXCC entity
- a State
- a County
- a Grid Square
- a CQ zone
- an ITU zone
- an IOTA Reference Number

TrustedQSL -- a specification and library for digitally signed QSO records that is used in LoTW