Also, in terms of restrictions, within Parliament there are always the restrictions that the House or committees will impose on themselves.
As indicated, and you referred to examples earlier, there are documents provided with redaction. It's up to each committee, on a case-by-case basis, to decide whether they want to accept the redactions that have been made and whether to insist on some and not on others and, if they're still dissatisfied, to report to the House.