We could use a different naming convention for a foreign key and still map that foreign key against the navigation property (using the ForeignKey data annotation does the trick). In a relationship, a navigation property is not required in the dependent entity, meaning that having a single navigation property on a principal entity is more than sufficient:

In the following code, the custom foreign key is mapped against the navigation property:

    public class Blog
    {
      ... // code removed for brevity
      public ICollection<Post> Posts { get; set; }    
    }
    public class Post
    {
      ... // code removed for brevity
      public int BlogSomeId { get; set; }
      [ForeignKey("BlogSomeId")]
      public Blog Blog { get; set; }
    }

The following image illustrates that the custom foreign key is mapped against the navigation property:

We have modified the foreign key to BlogSomeId and configured it against the navigation property which is the Blog of the Post entity, and it still works as expected.