Facebook users' most popular word during 2009 was the digital slang term 'FML', according to new data released by the company.
The data shows that the site remains primarily used by students, even though Facebook is increasingly trying to be represented as an ideal business tool.
Copying Twitter, Facebook has released the top words and phrases in users' status updates for 2009.
While Twitter regularly maintains the trending topics and makes them always accessible to users through their homepage, Facebook is releasing a year-end list, which it has called Facebook Memology.
Facebook Applications topped the list, but this is because Facebook groups together words and phrases related to each other. For example, just one Facebook game application called Farmville has 72 million monthly active users who constantly update their statuses.
The slang word FML came second. Data scientist Lars Backstrom gave an explanation of the term in a company blog post.
"People now use it simply to express some frustration with an aspect of their lives," he said. "We'll leave the 'F' open to your interpretation, but the 'M' and 'L' stand for 'My Life'," he said.
"The beginning of May appeared to be a seriously frustrating time for people, when students were busy with finals and the weather was rainy just before summer.
"We saw a lull in 'FML' in the summer months and, as expected, there was strong weekly periodicity to this term with it appearing most often on Mondays and Tuesdays."
The second most popular term used on Facebook was 'Swine Flu'.