What are Type I/II or Type II/V cements?
A Type II/V cement designation simply means that the cement complies with the requirements of ASTM C 150, Standard Specification for Portland Cement, for both Type II and Type V cements. It is quite common to find cements that comply with multiple cement designations such as Type I/II and Type II/V.
Question and answer courtesy of Portland Cement Association (PCA). More information is available at: http://www.cement.org/tech/cct_faqs.asp.