What is the nature and format of a Lenten Penitential Service in the Catholic Church?

Close to the Lenten season in the Catholic Church, I frequently see announcements for a **Lenten Penitential service** in Catholic parish weekly bulletins and websites, which is on a weekday, and seems to have a completely different liturgy than a regular mass. For example, in [this YouTube](https://www.youtube.com/watch?v=xUrO8Z7pzII) from a 2021 Lenten Penitential Service in the Edmonton area, Alberta, Canada, the priest started with a prayer followed by a Bible reading, a homily about repentance, a preface before examination of conscience, another prayer to forgiving others and ourselves, a reading of the whole text for examination of conscience (see the video description), penitential prayers, and ended with an invitation to come individually to the sacrament of reconciliation. It seems to assist parishioners for confession before the Easter celebration, which understandably is encouraged during the Lenten season, but unlike Ash Wednesday it's not an obligation. It doesn't seem to be prevalent since [Google search](https://www.google.com/search?q=%22lenten+penitential+service%22&oq=%22len&aqs=edge.0.69i59j69i57j0i131i433i512j0i433i512j0i131i433i512j0i433i512l3j0i512.3264j0j1&sourceid=chrome&ie=UTF-8) only yields 3,380 results. I hope the answer will address the following: 1. Is there a document from Vatican governing the format, or can it vary depending on country / diocese? If not, what are the necessary elements? 2. What is the sacramental nature of this service? 3. Is the text of the prayers in the service standard? Is the choice of Bible reading correspond to the assigned reading of the day, specially standardized for this service, or at the bishop/priest's discretion? 4. Why is it separated from Ash Wednesday? What was its origin? 5. What is the purpose behind this service? 6. Does a parish offer it more than one time per year? Can it be conducted upon parishioners's request?