I do not have any USCIS link with me now. I will update you if I find a direct link to this information.
As far as I know, one H1B cap is valid for 6 years and a company can use that cap to apply cap-exempt H1B petition. If the same company applies for H1B again it will H1B extension and if a new company is applying, it will be H1B transfer.
Alternatively, you may enquire with any immigration attorney and confirm this.