Requests the current object of particular type.

For instance, it can provide the current buffer to an IBuffer parameter.

description = "Copy the contents of the current buffer to the clipboard.")]
public static void CopyToClipboard([Current] IBuffer b) {
GUIUtility.systemCopyBuffer = b.content;

Or the current InputField if any are selected.

description = "Move cursor forward one character")]
public void ForwardChar([Current] InputField inputField) {
inputField.caretPosition += 1;
See also
ICurrentProvider for instructions on how to implement your own.