'Henry, what's a hista?' asked Bunny.

'A hista?' Confused, Henry turned away from Wendell. 'Where'd you hear that?'

'Online.' Bunny held up her phone for Henry to see the open Disney World Facebook page.

'Oh!' Henry chuckled. 'HISTA. I'm sure you remember there was a show in EPCOT called Honey I Shrunk the Audience. HISTA is an acronym to refer to it.'

'Like how our initialism is CBJ for Country Bear Jamboree,' Wendell chimed in.

'I'd forgotten about Honey I Shrunk the Audience,' said Bubbles.

'You mean HISTA,' said Beulah.

'Are there any more acronyms?' asked Bunny.

'EPCOT's an acronym,' said Wendell. 'It used to stand for Experimental Prototype Community of Tomorrow.'

'But fans hijacked it and changed it to Every Person Comes Out Tired,' Henry chuckled.

'There's mostly initialisms,' said Wendell. 'CBJ, IASW, BTM, MSEP, HM, MNSSHP, MVMCP -'

'But what do they mean?' asked Beulah.

'IASW is It's a Small World,' said Henry. 'BTM - Big Thunder Mountain. MSEP -'

'Main Street Electrical Parade,' said Wendell.

Henry nodded. 'Right. HM is Haunted Mansion. MNSSHP and MVMCP are -'

'Mickey's Not So Scary Halloween Party and Mickey's Very Merry Christmas Party,' Wendell finished.

'Why are they initialisms, not acronyms?' asked Bubbles.

'An acronym is letters that make up a word you can say, like EPCOT or HISTA or NASA,' said Henry. 'An initialism is letters you spell out. Like CBJ, BTM, or FBI.'

'What's FBI?' asked Beulah.

'The Federal Bureau of Investigation,' said Wendell. 'Don't get caught up with those guys.'

'Right. No. I thought it was a ride or something,' said Beulah.

'There's also abbreviations,' said Henry. 'Like how Pirates of the Caribbean becomes Pirates. And Walt Disney's Enchanted Tiki Room becomes the Tiki Room.'

'Oh.' The triplet girls exchanged glances and nods.

'Yeah, that makes a lot of sense,' said Bubbles.

These are the common abbreviations for the rides as used by guests, Cast Members (or CMs!), bloggers, bloggers, and people on Facebook groups.
Acronyms are frequently mistaken for initialisms, but they are not the same thing.