Traditional Culture Encyclopedia - Photography and portraiture - There are RM, DT, DV and PDF file formats. What do they mean?

There are RM, DT, DV and PDF file formats. What do they mean?

RM is a movie file, which is played by Storm Video or realone.

PDF is an e-book file, which can be read by a superstar reader or other e-book reading software.

DT, I don't know,

DV seems to be taken with a digital camera. ,,,, This is called DV.