I had a database that I made using SQL Server 2005 Express.
I then realised that the compact edition would make things easier for me in deployment as it is such a small project.

I converted the mdf file to sdf using http://www.primeworks.pt/

I never really paid much attention to the structure of SQL Server db before I converted and now it is deleted

When I look at the database using VB.NET 2008 it displays a directory tree style view.
It has DB.sdf -> Tables -> All my tables
but it also has DB.sdf -> Replication -> Subscriptions

Replication and Subscriptions are both empty.
What are they? Are they necessary?
Can I remove them?