In the text payload, a section called UDH (User Data Header) is optional but defines lot of advanced features not all mobiles are compatible with.

FORBES: French Hacker Claims That Every Single iPhone Ever Made Vulnerable To SMS Spoofing Bug

As Apple is using the reply-to address of a message's User Data Header to identify the origin rather than the raw source, receiving iPhone owners risk being fooled by a phishing attack (or just a dishonest acquaintance) that poses as a contact or a company.

ENGADGET: iPhone reportedly vulnerable to text message spoofing flaw

Some forge their e-mail header--the data above and below an e-mail that contains information about the recipient and sender.

FORBES: Spam Warfare

The data showed the average forces of a soccer-ball header were similar to those exerted on the head by punches from amateur boxers, according to Daniel Plant, a researcher in Imperial's department of mechanical engineering, who presented the data Friday at a helmet-safety science conference at the university.

WSJ: Soccer 'Header' Impact Likened to Hard Punch