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Using Babinet's theorem and certain results of the theory of short-range order originally developed for Cu3Au alloys it is shown that the diffuse scattering intensity in the electron diffraction patterns of the substoichiometric transition metal carbides is related to a short-range order of carbon vacancies. Numerical values for the short-range order parameters can be obtained by integrating over the total diffuse intensity within one repetitive unit in reciprocal space. To perform such calculations on VC0.75 an analytical function was identified which describes the shape of the diffuse intensity curves in reciprocal space. Making the simplifying assumption that the value of the diffuse intensity is 1 on the diffuse intensity curve and 0 everywhere else numerical values for the vacancy short-range order in VC0.75 were obtained. The results, represented as average numbers of vacancies in different coordination shells around a vacancy, agree with the general principles of vacancy arrangement found in ordered transition metal carbides and nitrides.
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