DBMS is MS Access - should have made that clear in my post, sorry.
Access allows the creation of custom field properties, meta-data, in essence, for a particular column. DAO provides very convenient access to this capability, but we really want to begin migrating away from DAO (understand the legacy app is about 350K LOC with DAO spread throughout) in our new development efforts.
The .Net DataColumn provides an ExtendedProperty that does much the same thing. However, it doesn't seem that ADOX provides that capability. I'm thinking we're going to have to create a special table to handle this. No big deal, but a bit of extra work.