What ISN'T included in SQL Server snapshot replication? When creating a publication in SQL Server 2012 I get the options to include articles of type:


tables
views
stored procedures
UDFs


Since this list didn't include user-defined types, I was expecting those NOT to be replicated. But happily they were! (i.e. user-defined table types were replicated)

So question: What CANNOT be replicated in SQL Server? Also, why WERE the types replicated? Do they count as 'tables'?
I know this might not be a full answer. But this is too long to put in a comment.

Reference:

https://docs.microsoft.com/en-us/sql/relational-databases/replication/publish/publish-data-and-database-objects

Publishing User-Defined Types and Alias Data Types


  Columns that use user-defined types or alias data types are replicated
  to Subscribers like other columns. The CREATE TYPEstatement for each
  replicated type is executed at the Subscriber before the table is
  created. In the case of user-defined types, the associated assembly is
  also copied to each Subscriber. Changes to user-defined types and
  alias data types are not replicated to Subscribers.
  
  If a type is defined in a database, but it is not referenced in any
  columns when a publication is created, the type is not copied to
  Subscribers. If you subsequently create a column of that type in the
  database and want to replicate it, you must first manually copy the
  type (and the associated assembly for a user-defined type) to each
  Subscriber.


What CANNOT be replicated in SQL Server?

Anything not listed here cannot be replicated.