All XSD to ASN.1 information item mappings are as specified in the ITU-T X.694 standard, a free copy of which is available at the following URL:
http://www.itu.int/ITU-T/studygroups/com17/languages/X694pdf
The only non-standardized item is the module name used for the generated ASN.1 module. XSD2ASN1 assigns module name as follows:
It will attempt to use the last delimitted item at the far right in the target namespace declaration. For example, if the target namespace URI is "http://foo/bar", "Bar" will be used as the module name (note the first letter was capitialized as per X.694 naming rules)
If the target namespace is not in a standard URI format or if the last delimitted name contains special chanracters or is very long, then the name of the original XSD source file is used.