Here is a link to the schema for an Advanced Shipping Notification document defined by the American Institute for Steel Construction.
And here is the format for submitting a summary of an employee's annual earnings(T4) to the Canadian government.
The ASN has tags such as BillOfLadingReference, TransactionDateTime, ShipmentDateTime, ShipmentWeight and is nicely nested to represent the data relationships between the elements.
The T4 however is a doozy. Here are few of my favourite tags: tot_empr_eip_amt, tot_itx_ddct_amt, cmpn_rpay_empr_amt, shr_opt_d1_ben_amt. It structure is more of a laundry list of parameters than any kind of logical document.
The whole point of XML is that the data is stored in a readable format. If the document is filled with unintelligible tags it is hardly meeting that goal.