Final answer:
IRS General Counsel Memoranda aid in creating Revenue Rulings and Private Letter Rulings, offering in-depth legal analyses rather than merely summarizing regulations or indicating short-term decisions.
Step-by-step explanation:
IRS General Counsel Memoranda are legal analyses that assist in preparation of both Revenue Rulings and Private Letter Rulings. These internal documents provide in-depth material and legal reasoning that helps the IRS develop official guidance and positions on various tax-related matters. Contrary to the options provided, they do not solely convey the IRS's decision to acquiesce or non-acquiesce in a court decision, nor do they simply summarize and explain published IRS Regulations, and it's inaccurate to say they have only short-term value, as they can be influential in understanding the IRS's interpretation over time.