ATTORNEY GENERAL Under provisions set out in the Texas Constitution, the Texas Government Code, Title 4, 402.042 and numerous statutes, the attorney general is authorized to write advisory opinions for state and local officials. These advisory opinions are requested by agencies or officials when they are confronted with unique or unusually difficult legal questions. The attorney general also determines, under authority of the Texas Open Records Act, whether information requested for release from governmental agencies may be held from public disclosure. Requests for opinions, opinions, and open record decisions are summarized for publication in the Texas Register. The Attorney General responds to many requests for opinions and open records decisions with letter opinions. A letter opinion has the same force and effect as a formal Attorney General Opinion, and represents the opinion of the Attorney General unless and until it is modified or overruled by a subsequent letter opinion, a formal Attorney General Opinion, or a decision of a court of record. To request copies of opinions, phone (512) 462-0011. To inquire about pending requests for opinions, phone (512) 463-2110. Opinion. DM-438. (RQ-918) The Honorable C. E. "Mike" Thomas III, Howard County Attorney, P.O. Box 2096, Big Spring, Texas 79721, concerning ad valorem taxation of equipment used to produce minerals on mineral leasehold estate, and related questions. Summary. For purposes of ad valorem taxation, the value of mineral production equipment must be appraised separately from the value of the mineral leasehold interest for which the equipment is used. Determination of the applicable statute of limitations period for collection of delinquent ad valorem taxes turns upon whether the property is real or personal. If the property is personal, taxes on it may not be collected by suit or seizure if they have been delinquent for more than four years. If the property is real, the twenty-year limitations period applies. Mineral production equipment cannot be categorically classified as either real or personal property. Instead, determinations of the proper tax classification of production equipment must be made on a case-by-case basis. TRD-9706266 Request for Opinion ID# 39533. Request from the Honorable David Counts, Texas House of Representatives, P.O. Box 2910, Austin, Texas 78768- 2910, concerning whether a former regent of the Texas State Technical College System may be appointed executive officer of the system. TRD-9706267