An atomic tag is special, it doesn't need any other tags to go with it. Tags in XML are case sensitive. Basic AIML Lets jump right in with a very basic AIML file. This will be the first and last tag of each seperate AIML file. A category contains the information for one response.
Patterns are what the chatbot matches.
Notice the pattern is in all caps and has no punctuation. This is because of the various things alice does to the text before she matches it. Patterns must be in all capital letters with no punctuation. An AIML file can contain many many categories. In fact, some of the ones included with alice litterly contain thousands.