The presumption of access and the balancing test
Most withholdings aren't automatic. Outside of records that statutes specifically close, a custodian must apply a “balancing test” — weighing the public interest in disclosure against the public interest in keeping the record confidential. The presumption favors release.
That means a generic “it's confidential” isn't enough; the authority has to articulate a specific harm that outweighs disclosure.
Common statutory exemptions
Frequent categories under § 19.36 and related law include personnel records of certain investigations, some law-enforcement records (especially ongoing investigations), records whose disclosure is barred by other state or federal law, and certain personally-identifying information.
Even where an exemption applies to part of a record, the authority must release the segregable non-exempt portions.
When in doubt, push back
Exemptions are construed narrowly. If a denial cites an exemption that doesn't obviously fit, ask the authority to explain how it applies to your specific records — and consider the challenge options.