001975 John obtains a new captchalogue card. Likely a remnant from when captchaloguing and the sylladex would have actually been a relevant mechanic through the whole comic.
001976 Of course he captchalogues the card because WACKY SHENANIGANS.
001977 is the first instance of music in the comic. This is actually incredibly important. Music came to be one of the defining characteristics of Homestuck and honestly I have to say its one of the few elements that go all the way to the end without starting to suck.
This is the page that introduces [s] as the convention for sound pages.