> For the complete documentation index, see [llms.txt](https://docs.wellcomecollection.org/transcribe-wellcome/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wellcomecollection.org/transcribe-wellcome/research/documentation-systems/photographs.md).

# Photographs

PHO numbers

PHO series begun by Pender-Davidson in December 1928. Continuous sequence to 1987. Negative numbers noted usually refer to Wellcome Images M sequence.

Registers PHO 1 to PHO 15277 (WA/HMM/IC/1/9-24)

Index cards PHO 1 to PHO 2234 (WA/HMM/IC/3/C.1-C.14)

Pre-1918, a few photographs were accessioned, probably by the library rather than the museum, and given P references (see [section on Prints and Drawings](https://docs.wellcomecollection.org/transcribe-wellcome/researching-the-museum-and-library/documentation-systems/prints-and-drawings))