- Acquired: purchased by library
- Film: 35mm Black-and-white Negative
Note on the box: "Madrid. Biblioteca Nacional. Cod. 4866 & Escorial Ms. Χ-I-5. Photius' letters."
Library ID slip: Escorial griego Χ-I-5. 80-228. Mr. Laurdas."
On the acquisition list: "Microfilms of Mss. of Photius' Letters and Homilies, received March 1950-Sept. 1951. Complete Mss." (4866 only; but Escorial appears to be from the same age).