Thanks
That's a really useful link for our developers, but I'm not sure it helps our more data driven users as much - the package route feels a little "heavy" for them - especially when they just want to iterate locally over different code.
I'll keep looking at it and digging around - we can't be the only people looking for a lightweight way of sharing code between markdowns (although, if we are, then maybe that suggests we are doing some other things wrong too 
)