Anyone that has worked using Unreal engine will know that there can be a huge amount of various assets that get used and imported into Unreal Engine Projects. So it has been standardised to put certain prefixes before different types of files to help identify them quickly and efficiently. – If you are working in a game or just creating cinematics it is good practice to use these naming conventions.

E.g. SM_vampirecar = Static Mesh vampire car. 

Unreal Engine Naming Conventions below:

BP_ Blueprint
SK_ Skeletal Mesh
SM_ Static Mesh
AD_ Apex Destructible Asset
AC_ Apex Cloth Asset
MT_ Morph Target
ST_ Speed Tree
PS_ Particle System
LF_ Lens Flare
VF_ Vector Field
S_ Sound
SC_ Sound Cue
M_ Material
MI_ Material Instance
MITV_ Material Instance Time Varying
MF_ Material Function
MPC_ Material Parameter Collection
T_ Texture
SP_ Sprite
SS_ Sprite Sheet
TC_ Texture Cube
RT_ Render Target
PM_ Physical Material

If you notice a mistake or think an update is needed please do add a comment below – Thanks!