Coincidentally, ASN.1 (specifically it's DER encoding) is used in X.509v3, better known as TLS certificates. For a taste of the crazyness that ensues check out

Coincidentally, ASN.1 (specifically it's DER encoding) is used in X.509v3, better known as TLS certificates. For a taste of the crazyness that ensues check out Peter Gutmann's x.509 style guide [1]. Personal highlights: * Many different ways of encoding a simple string, with some very obscure encodings. * SET OFs are sorted in the DER encoding, to ensure consistent bytestreams. This sucks for embedded systems. * OIDs (unique identifiers for things) are unbounded. [1] https://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt https://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt