IDNA talks about "domain name slots". There are "internationalised domain name slots", probably meaning a domain name slot that uses the native character set of the context the slot is in, though IDNA is having all non-ASCII domain names being in ACE. And there is a "generic domain name slot", which should really be called "ASCII only domain name slot" because it is not generic.
Reading more in IDNA you find that it a domain name is to be put in a "ASCII domain name slot" it has to be converted into ASCII. But you will also find a section about entry and display in applications. In it there is talk about different places where domain names can appear, including that non-ASCII character should be used if allowed. The probably first place where non-ASCII domain names will be used is the web. This is also the place where encoding domain names using ACE is not really needed (as it already can work without it). When you look at the web, it is the URL people will use non-ASCII it. They will have them both in the domain name and in the path. Where do the user enter URLs? In the location field to open new pages, and in the HTML code in links. People will NOT enter domain names using ACE. Links in HTML code will contain non-ASCII! As the context of a HTML document have a defined charactert set, URLs embedded in the will be written using the same character set. The text in the IDNA draft may be interpreted as you must use ACE encoded names in URLs inside a HTML-document. Just forget it. It must be possible to use the character set of the context of the HTML document. People will not write ACE! Only automatic software will do that. IDNA will therefore not be really usefull untill the important applications handle conversion to/from ACE automatically totally invisible to the user. The important applications include the web browser, the e-mail software and the operating system software handling host names. Dan
