the mysql docs
http://dev.mysql.com/doc/mysql/en/create-table.html
suggest you can bind comments (metadata) to columns under mysql 4.1
this is very cool — it allows folks to store notes about columns etc. in the DB itself
metadata is a very good thing
it would be great ifd SQLyog allowed you to create/modify column level comments
there does seem to be support for table level comments (under advanced features, i think)
but column level comments are worth supporting too