Yes, be careful with 'typicals'.....
What size is the opening and what type of slab is it (one-way, post tensioned, thickness, etc.)?
Are they bracing the crane to the slab?
Typically want to leave a key for future slab infill, then add reinforcing around the opening (and diagonal reinforcing at corners) to 'carry' the concrete around the opening.
Even if you find a 'typical' make sure you check it works for your application.