program custom fields?

Sort of - Marketo would call it tagging a program. However, these custom tags will not sync to SFDC.

Yeah that woudln't achieve what I'm looking for. that would be tagging the program (definining a property of the program), not creating a field on that program that could be uniquely defined for each contact (e.g. "program registration number"). the only workaround I see right now is available to sfdc users by creating a custom campaign field and having that field sync over to marketo. 

A campaign field won't sync to a lead record in Marketo. You might be interested in the discussion on this thread: Including Campaign Member Fields

For a value that is unique to each contact on a particular program, what you really want is a campaign member field. In a nutshell, you create that field on the lead/contact where Marketo can populate the value and then build a SFDC workflow rule that copies that value to a campaign member field when the lead/contact is added to a campaign.

Thanks Delinda,

I think that workaround is not particularly scalable, when you need to maintain unique fields on the lead profile for eahc program. I wonder if the campaign custom field sync can be enabled this way

http://community.marketo.com/MarketoArticle?id=kA050000000KyrHCAS

using the object sync configuration. 

I use the same lead/contact field for every program. Once the SFDC workflow passes the value to the appropriate campaign, I delete it from the lead/contact so that it can be populated again if they're added to another campaign.

My understanding of the custom object sync is that it will only allow you to read and filter on those objects, but not write to them from Marketo.

Adding custom fields to Programs is on the roadmap but not scheduled into a release in 2013.  

Thanks Cheryl and Delinda,

I think this answers my questions.