ConnectedComponents[g] gives the connected components of the graph g.ConnectedComponents[g, {v_1, v_2, ...}] gives the connected components that include at least one of the ...
UnrankGrayCodeSubset[n, l] gives the n\[Null]^th subset of list l, listed in Gray code order.
UnrankSubset[n, l] gives the n\[Null]^th subset of list l, listed in some canonical order.
All the functionality in Miscellaneous`PhysicalConstants` is now available through the newly created Physical Constants Package.
DefaultFormatType is an option for cells that specifies the format used for displaying expressions in a newly created cell.
DefaultInlineFormatType is an option for cells that specifies the format used for displaying expressions in a newly created inline cell.
MultilaunchWarning is a global option that specifies whether a warning is given when you try to modify user preferences while running two copies of Mathematica simultaneously.
Regularization is an option for Sum and Product that specifies what type of regularization to use.
MenuCommandKey is an option for cells that specifies the keyboard shortcut to be associated with a style listed in the Format \[FilledRightTriangle] Style submenu.
RandomPermutation[gr] gives a pseudorandom permutation in the permutation group gr.RandomPermutation[gr, n] gives a list of n pseudorandom permutations in the permutation ...