If you search for “Pokémon X Update 1.5,” you will not find it on Nintendo’s servers. The last official update for Pokémon X and Y was Version 1.4 (released December 12, 2013, to patch the Lumiose City save glitch and add support for the Pokémon Bank). So why does “1.5” exist in the ROM/CFW community?
Version 1.5 is a fan-made designation for a modded update that includes: Pokemon X- Update 1.5 3DS -World- CIA -Region F...
For purists, this is not an official patch. For homebrew enthusiasts, it is the definitive way to run Pokémon X from any region on any 3DS without cartridge swapping. If you search for “Pokémon X Update 1
This indicates the file is meant for the Nintendo 3DS family (original, 2DS, New 3DS, New 2DS). It will not work on a PC emulator without conversion, nor on an unmodified 3DS. For purists, this is not an official patch
This refers to patched files that ignore the 3DS’s region locks. A Japanese Pokémon X CIA (normally only playable on a Japanese 3DS) can be installed on a US or European console if the update or the base game has been region-patched. A “World” CIA is pre-patched to work on any region’s console.
Again – a scene-modified update file. Typically packaged as a .CIA file ranging from 30MB to 120MB. It patches the base game to appear as “Ver. 1.5” in the System Settings menu.