After every attribute name or attribute value there must be a TAB character (ASCII 09 decimal). At the end of lines TABs are not necessary but they can be there.
It is a good practice to begin new attribute name or value immediately after the TAB although spaces before and after the TAB are ignored. Other spaces, which occur in attribute names and values are not ignored and they are accepted as regular printable characters. A good practice is to replace such spaces with underscore characters '_' when possible.
Exceptionally, there can be two or more TABs one after other. The meaning is that the attribute name or value which should be between them is actually unknown. The same case is when there are only spaces between TABs, because such spaces are ignored. A good practice is to mark unknown values by a '?'.
© 2001 LIS - Rudjer Boskovic Institute
Last modified: April 18 2018 18:23:13.