More than a comprehensive description is in the article Events in МetaТrader 4.
Translated from Russian by MetaQuotes Software Corp.
Original code: https://www.mql5.com/ru/code/8234
The library contains the functions that are intended to split the access to the trade flow.BZ_TL_SkylineM
The author insists that users may utilize this indicator as an external interface for all other indexes.