It's so simple. The format is the shape of things. Anything in a format
spec that doesn't lay out bytes is extraneous.
In that case, I can put the ASN.1 format in three sentences:
1. First comes the type code of 1 or more bytes. You have to look at each byte to see if there is another byte.
2. Second comes the length of 1 or more bytes. You have to look at each byte to see if there is another byte.
3. Next comes the number of bytes specified by the length.
While all that is indisputably true, it's hardly sufficient to do anything useful.