1. Simple list of mandatory fields
This is the typical and most simple use-case: it's a check on a the list of table's mandatory fields. Just look at formula in the Validation column.
2. Conditional validation
It is possible to combine the mandatory fields according to different conditions according to status. Conditions can be composed via Validation.ColumnList chains (see Composable Validation column, if you want to have multiple, different validation columns) or in a single column (see Composable Validation Alternative column)
Custom Validation Message
Composable Validation Alternative