A translation of the background in Stelsa’s route. Pretty much exactly as you would expect. 

Transcript:
- SUNRISE: [Illegible]

- TENACITY: give up already lowbloods [Referencing Hang in there, Baby]

-  [A very organized file system. With a sudden jump in letters from D to Q]

None of the books or notes appear to have any Alternian or English writing except for one book:

image

EDIT: Additional info submitted [original post] from @thegreathomestuckreread:
 

- “ The visible text under the “SUNRISE” poster says “SHADES BAN”. “

-  “ On the filing system, the second box from the right is WT-WV, the one below it is WV-WW, and the box on the bottom left is D-E. “