@Proof Positive  
Not sure if meant to be canon, but lots of characters share the same cutie mark. And then there are non-ponies that need ID.

What if their cutie mark is used in place of their name on ID cards? :O

@ThePonyTheorist  
I’m not interested in that aspect of the answer. I say that for simplicity of audience understanding, printed words in Equestria for comics or animation should be in English, or the primary language of the audience. If the concept of “human visitors to Equestria don’t know or understand the language” is a key element to the narrative, then the printed script can look weird.

@Dogman15  
Printed words are rarely english, but even in the very first episode, Equestria has had its own written language. See Predictions and Prophecies.
 
Over time, this language has changed from heiroglyphics, to ‘squiggles’, to some kind of more complex alphabet-based system. The changelings seem to have their own scripts, which contains much more angular lines instead of the curved shapes of Equestrian characters.

The real answer is that they once used real English for printed words in the show, but then either realized or were told that that wouldn’t fly in countries that don’t use English as their primary language, so from then on, they would slightly modify the English text so it’s somewhat recognizable, but not explicit English. Still heavily based on English, but not in a way that would blatantly stand out and potentially confuse kids in other countries. Simultaneously, to American kids, they might not think anything of it.
 
Other cartoons get away with English text, right? But do they go to a lot of trouble to change that text for other foreign dubs?

It would make more sense if it said “sparkle”

@Background Pony #A966  
Because the word spoken is not library. For all we know, the equestrian word for library is “Einsald”

@Background Pony #E5F0  
That doesn’t go a particularly long way to explaining why they have two runes for the same sound.

 
Closed

7L’BR7 U U

Not using a pony-based writing like the first episode had was a mistake.

@ThePonyTheorist  

 
To be honest, I’ve made a similar theory to that argument and mentioning Kanji in a video.

I’ve made my own analysis of the language  
In moments where written Equestrian is visible, letters tend to more accurately translate into words. This is similar to japanese Kanji, but they could have a system for individual letters.
 
The text also seems to go in reverse, or at least the letters adding sounds…
 
There are more instances of text with translations which could use similar treatment
 
This one also

or it could just be gibberish.

I’m pretty positive on this subject, that screen-cap might not be rational. There aren’t any evidence that clarifies how ponish can be translated to English. Suggesting that “library” wouldn’t be the proper translation, instead it might be some other typo, because normally you wouldn’t see the term library in large text on a license card, but that’s just my speculation.

@Red Cedar  
Suuure is it:  

Yeah, I think written Ponish is vastly different from English. Or we have to accept the show us dubbed into our language.

@Background Pony #A966  

 
Because it’s not English? R is a transliteration of the rune.

Why do both Rs look different, then?

I’d love to see fully translated ponish