Add/Remove Cell Tags opens a dialog box that allows you to add or remove cell tags associated with the selected cell(s).

Check Spelling opens the Check Spelling dialog box and searches for misspelled words.

Array[f, n] generates a list of length n, with elements f[i]. Array[f, {n_1, n_2, ...}] generates an n_1*n_2*... array of nested lists, with elements f[i_1, i_2, ...]. ...

CreateDirectory["dir"] creates a directory with name dir. CreateDirectory[] creates a directory in the default area for temporary directories on your computer system.

DynamicEvaluationTimeout is an option for displayed objects, cells, and notebooks that specifies the timeout in seconds for any Dynamic computations they contain.

EdgeAdd[g, e] makes a graph by adding the edge e to the graph g.EdgeAdd[g, {e_1, e_2, ...}] adds a collection of edges to g.

FindHamiltonianCycle[g] finds a Hamiltonian cycle in the graph g if one exists.

FixedPoint[f, expr] starts with expr, then applies f repeatedly until the result no longer changes.

GainMargins[sys] gives the gain margins of the linear time-invariant system sys.

Heads is an option for functions which use level specifications that specifies whether heads of expressions should be included.