.pdf or .mp3 Internet addresses could soon appear under a new proposal, but domain suffixes consisting entirely of numbers would be rejected.

The ICANN (Internet Corporation for Assigned Names and Numbers) is looking for feedback on security and operational issues that may arise from the introduction of the new domain names as early as this year.

ICANN concluded it would be much too difficult to track which extensions are popular enough to prohibit and allowing them shouldn’t confuse the major web browsers which already assume that the address is pointing to a page rather than a file. ICANN has also said that it considered prohibiting suffixes that match common file extensions (such as .doc for word files, .exe for executable and .jpg for photos).

.123 would be banned because domain names are easy to remember substitutes for IP addresses (Internet Protocol) and so allowing all suffixes might result in a web address that clashes with an IP address and so confusing browsers. When the criteria for its proposal are finished ICANN will start taking bids from outside companies for domain names. So a .pdf domain would also appear only if an applicant comes forward and wins approval. ICANN has yet to determine how many new names it will accept to join ".com" and more than 250 others already in place.