大見出しでの冠詞の使い方

Someone asked me a great question today about an article that we studied. The title of the document was "Lingua Franca", and it started with a sentence from Wikipedia that read:

• English as a lingua franca (ELF) is the use of the English language "as a common means of communication for speakers of different first languages”.
• lingua franca〈イタリア語〉〔異なる言語を話す人同士の〕共通語、補助言語◆通例、通商を行うときに使われるもので、ピジン英語（pidgin English）などが含まれる。(definition from Eijiro on the Web)

The question was:

Why is there no article before Lingua Franca in the title? ... the first sentence has an article before "lingua franca".

• article《文法》冠詞 (definition from Eijiro on the Web) 

If you pay attention to headlines, you will notice that articles are almost always dropped. Here are some examples from today's news:

• Turkish, Lebanese hostages home after release deal ←Turkish and Lebanese hostages are home after a release deal.
• Strike could have long-term impact on unions ← The strike could have a long-term impact on unions.
• Car bomb, clashes kill over 30 near Syrian capital ←A car bomb and clashes have killed over 30 near the Syrian capital.

I was taught that there is a historical reason for that. Newspapers wanted to make the headline as big as possible so that the newspaper would sell well. If they removed the articles, they could make the headline shorter and thus bigger. Since native speakers could guess the articles from the context (especially since it is written and not spoken), it was thought to be OK.

Here's a good article on the other grammar points in headlines:

http://chronicle.com/blogs/linguafranca/2013/02/18/the-grammar-of-newspaper-headlines/

Thanks for paying close attention!