“参考点”、“以……为参考”、“参照物”are usually for coordinates（坐标）, time and position changing, eg, 坐标原点为参考点。//以河岸为参考，小船在运动。//在"We had finished before he arrived."这句话中， finish是以过去的动作he arrived为参考的，所以要用过去完成时had finished。在英语时态中要注意时间的参照点。

I feel 基准点 is the best.

参考位置

I think it depents on the situation. It could be translated to 参考内容 in your example I think.

I think 基准点 is better.