AA7BQ, Owner QRZ.com

Effective today, the QRZ Callsign database is changing the
way we serve callsign data to our web (browser) based users.
These changes have been brought on by a steadily increasing
number of automated systems that access the QRZ data in
so-called hidden or stealth mode. Such systems create a
significant load on the QRZ servers and in doing so, deprive
ordinary users of the performance that they deserve.

These robots (or 'bots') come in many forms. Some are
designed to scrape the entire website for every piece of
information we have. Others, known as "log checkers" are
programs written by hams that repeatedly query the QRZ
servers while working through lists of 10's of thousands of
callsigns, doing it as rapidly as possible. Finally, some logging
programs provide "auto fill" features that use the QRZ
servers in the background to fetch callsign data as soon as
the user types in a callsign.

For the past several years, QRZ has provided an XML
Data service that was specifically designed to serve automated
requests such as those described above. The XML service is
an extremely lightweight and flexible system that places less
than 1/10 of the load on our database that a "stealth" callsign
lookup does on our regular pages. In addition, our advertisers
are being deprived of ad exposures by these programs which
routinely ignore or discard all such non-callsign data as they
scrape our site.

Today's changes address these issues with a new set of
constraints that we have developed with the goal of providing
fast and fair access to all QRZ users. The following is a
summary of what these measures mean:

Callsign data, including name, address, and other QSL and
logging information will be shown only to registered users of
QRZ who are logged in at the time of the request.

Guests that have not logged in will still see the callsign
Bio page and pictures, but no callsign information will be shown.

Registered users who are logged in will see the full detail
on callsign pages.

Ham users, i.e. those whose user name matches a callsign
in our database, are limited to 150 callsign page lookups per day,
not including their own callsign page.

Non-ham users, i.e. users who aren't hams or don't have a
username that matches one of our callsigns, will belimited to
25 callsign lookups per day.

QRZ subscribers, of any type, are granted unlimited daily
access to the QRZ callsign data.

These limits are designed for fairness and the vast majority of our
ham users will never be affected by them, aside from the new
requirement that you must be logged in to see callsign data.
Note as well that when looking up or viewing your own callsign
page that the act does not count against your daily lookup limit.

We ask for your support in accepting these changes and
understanding that they were necessary in order to maintain
the high level of service and support that our users have
grown accustomed to.