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Section 6.11.7 of the C standard [ISO/IEC 9899:2011] states that "the use of function definitions with separate parameter identifier and declaration lists (not prototype-format parameter type and identifier declarators) is an obsolescent feature."
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Search for vulnerabilities resulting from the violation of this rule on the CERT website.
Related Guidelines
ISO/IEC 9899:2011 Forward Forward and Section 6.9.1, "Function definitions"
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