[Native]

From the electronic copyright office (eCO) FAQ: What works may be registered with electronic deposits?
The following classes of works may be registered in eCO with electronic deposit copies:
1. Unpublished works;
2. Works published only electronically;
3. Published works for which the deposit requirement is ID material (see the Special Deposit Requirements section of Circular 1 for more on ID material);
4. Published works for which there are special agreements requiring the hard copy deposits to be sent separately to the Library of Congress.
All other classes of works may be registered via eCO (application and fee payment) but require hard copies of the work(s) being registered.

It would have been nice if something in there would have mentioned the deposit requirements after publishing. Ah-well. Ignorance was bliss.