Sequence is automatically spliced in:

Splice a sequence of elements three times in a list:

Replace with a sequence that is automatically spliced in:

Completely flatten out all lists in the argument to a function:

Conditionally add an element to a list by using Apply to delay the Sequence until evaluation:

A sequence of arguments matched by __ is treated as a Sequence object:

## represents sequences of arguments by Sequence objects:

A sequence with one argument acts like Identity:

Functions that are HoldAllComplete do not automatically splice in Sequence objects:

Functions that have attribute HoldAll but not SequenceHold do automatically splice:

An empty Sequence[] will evaporate inside any head except those with special attributes:

Nothing will only disappear inside lists:

Splice a sequence of elements in any expression:

Splice[…] will only splice the elements inside lists by default:

Specify the head into which the elements can be spliced:

Most Wolfram Language functions automatically splice in Sequence objects:

Assignment and replacement functions have the attribute SequenceHold: