DEO? Are we talking about Caterpillar? If so, which info do you need?
It really depends what type of system you are going to use the oil in. If it's just a hydraulic system, the fluid only needs to be:
- clean enough for economic filter life
- non-compressable, no foaming
- right viscosity
In this case, the hydraulic oil only serves as a medium. Therefor you see so many differentiations, one OEM uses engine oil, the other a straight hydraulic oil, another ATF, etc.
@Michael: Can you give an example of a typical UTTO/STOU characteristic which may be required for a regular hydraulic system?