Related Clues:

• Contained
• Shut in
• Surrounded
• Hemmed in
• Start of a letter accompanying a manuscript
• Confined
• In the envelope
• Like a packing list
• Like SASEs
• Included
• Placed in an envelope
• Shut up or included in an envelope
• Surrounded completely
• Surrounded on all sides
• It's in there, so shut up!