concatenation
In formal language theory and computer programming, string concatenation is the operation of joining character strings end-to-end. For example, the concatenation of "snow" and "ball" is "snowball".
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KERI related
In CESR Concatenation is an important property of CESR's Composability; it is associative and may be applied to any two primitives or any two groups or sets of concatenated primitives.
The composability property of CESR allows us to create arbitrary compositions of primitives via concatenation in either the text or binary domain and then convert the composition en masse to the other domain and then de-concatenate the result without loss. The self-framing property of the primitives enables de-concatenation.