Commentary by Mark Wahl, CISA
Organizing principles for identity systems:
Hello World: 90 years of user-centric graphics design in a global virtual community (20070721)
Those who work in user-centric identity management and are not ham radio operators should have read Hello World: a life in ham radio, by Danny Gregory and Paul Sahre, published by Princeton Architectural Press.
This is a QSL card.
Whenever hams connect on the air for the first time, they exchange specially designed postcards in the mail.
These QSL cards are physical proof that the radio contact actually took place.
Each ham's card is different, featuring the call sign for his station, details about the call and the gear used, and words and pictures that tell more about himself and his home.
In a basic sense, a call sign of a ham radio operator is a public identifier, that (until recently) was administratively assigned and arbitrary.
"When he's on the air in his own ham shack, a ham's call sign is his identity, far more so than his legal name. He must announce the sign at least once every time minutes during a contact and again when he signs off. It's not unusual for a ham to emblazon his call sign on his license plates and clothing."
The convention of a subsequent exchange of QSL cards between two hams after they have participated in an interaction by radio is a 85-year old protocol that still is useful in portions of the world with no Internet and infrequent postal handling (QSL bureaus provide store-and-forward and bulk delivery).
QSL cards were tied to the ham's contact log: in the US until the 1960s (and longer in other countries), radio operators were required to keep a log of each contact they made, as this log could be audited by the government.
More interesting, however, to the user-centric case, is the design and contents of the QSL card. Like business cards, de-facto standards govern a QSL card's overall shape (rectangular), maximium dimensions (QSL cards shouldn't be larger than an index card), and some of the text fields on the cards (QSL cards must have sender and receipient's call sign, frequency, and date and time). Unlike business cards, QSL cards are designed by the individuals identified on them (and often handwritten, self-printed or printed by their local stationer), and within the overall constraints of QSL cards, hams have full flexibility to express themselves in colors, images, additional information about themselves, which in a short exchange of morse code or highly filtered voice it might not be possible to convey...
