Clarification regarding MBED_TICKLESS

Hi all!

I’d like a little clarification regarding what #define signifies deep sleep availability for a board and how MBED_TICKLESS relates to that. I see three defines that have to do with sleep: DEVICE_SLEEP, DEVICE_LPTICKER, and MBED_TICKLESS. My confusion is that Mbed doesn’t seem to have any defines that specifically indicate the availability of deep sleep. I know, at least, DEVICE_LPTICKER and DEVICE_SLEEP must be defined to enable deep sleep. But how does MBED_TICKLESS relate to that?

Is it valid to have LPTICKER and SLEEP defined without MBED_TICKLESS? Can the board sleep without MBED_TICKLESS?

Also this page: claims that a target must have support for Sleep and LPTicker to support MBED_TICKLESS but there is a MBED_CONF_TARGET_TICKLESS_FROM_US_TICKER #define which implies to me that LPTicker does not need to be supported to use MBED_TICKLESS. Does the documentation just need an update or am I missing something?