German to English Bus/Financial Finance (general) Transfer pricing guidelines

I'm not sure what this term means. It appears in the following sentence:

Anpassungsrechnungen, die allein auf griffweisen Schätzungen und nicht näher begründeten "Erfahrungswerten" beruhen, reichen nicht aus.

I've searched for this term on the web, and it seems to pop up usually related to fingering techniques for flutes. "Holding"?

Any help would be greatly appreciated!