This blog is updated daily.
A general description is here.
‘R CMD check’ does more thorough checking of declared packages and namespaces. It reports
• packages declared in more than one of the ‘Depends’, ‘Imports’, ‘Suggests’ and ‘Enhances’ fields of the ‘DESCRIPTION’ file.
• namespaces declared in ‘Imports’ but not imported from, neither in the ‘NAMESPACE’ file nor using the ‘::’ nor ‘:::’ operators.
• packages which are used in ‘library()’ or ‘requires()’ calls in the R code but were already put on the search path _via_ ‘Depends’.
• packages declared in ‘Depends’ not imported _via_ the ‘NAMESPACE’ file (except the standard packages). Objects used from ‘Depends’ packages should be imported to avoid conflicts and to allow correct operation when the namespace is loaded but not attached.
• objects imported _via_ ‘:::’ calls where ‘::’ would do.
• objects imported by ‘::’ which are not exported.
• objects imported by ‘:::’ calls which do not exist.
See ‘Writing R Extensions’ for good practice.