what means "frozen cost"?

Hey guys, need a hand here.

Any professional knows the meaning "frozen cost"?
In any fields, including Finance, industrial, or whatever aspects you have idea.

thanks for your help in advance.

Suppose you have a company that makes pens. YOu buy each pen for $1.00. Then you color it and sell it for $1.50. $1.00 that you spend to buy the pen is your frozen cost that you set at the begining of your fiscal year. This cost may change during the year, but you go by the 'frozen' cost in your accounting books. The cost that keeps changing during the year is 'current cost'. Later you adjust your books accordingly.