Construction Invoicing Index. Official Construction Invoicing Index of the Schweizerischen Zentralstelle für Baurationaliserung CRB (Swiss Research Centre for Rationalization in Building and Civil Engineering, CRB). Neutral index with pre-printed lettering in French. Stable brown cardboard. Division: 26 parts. Properties: Official Construction Invoicing Index of the Swiss Research Centre for Rationalization in Building and Civil Engineering, CRB.