In law, a question of law (also known as a point of law) is a question which must be answered by applying relevant legal principles, by an interpretation of the law. An answer to a question of law as applied to the particular facts of a case is often referred to as a "conclusion of law".

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Note added at 4 hrs (2007-02-14 05:00:46 GMT)
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I have also found another useful description:

Conclusion of Law: a judge's final decision on a question of law which has been raised in a trial or a court hearing, particularly those issues which are vital to reaching a judgment. These may be presented orally by the judge in open court, but are often contained in a written judgment in support of his/her judgment such as an award of damages or denial of a petition. In most cases either party is entitled to written conclusions of law if requested.

Reference: http://legal-dictionary.thefreedictionary.com/conclusion of ...