Does this remote control perform all the functions of the original remote?
Yes, the replacement remote performs all the functions, even when the original remote controls several devices. In the replacement remote we can program the fields of different devices (TV, DVD, SAT and AUX), this way we can include all the functions of the original remote control. If you see the keymap (instructions on the remote control) you can check that all the functions are present.
What is the Shift key on the replacement remote used for?
The Shift key allows you to double the number of functions that the replacement remote control can perform. For example, pressing Shift followed by the Power key (Shift + Power) performs a different function than when you press the Power key directly.
Not all the remotes need to use the Shift key, only those that due to their large number of keys can not execute all the functions with direct keys.
How can I know which keys of the replacement remote control perform the functions of the original remote?
When we send the remote control, we also send a document with the correspondence of the keys between the replacement and the original remote controls which allows you to know how to perform the functions of the original remote. Sometimes it is available on the web so you can download it.