元老 (yuánlǎo) is a term for a veteran or old leader, but in the context of the Chinese Communist Party, it refers to the Eight Elders. These senior leaders, headed by Deng Xiaoping, held substantial power during the 1980s and 1990s. In the English-speaking world, these men are often sarcastically called The Eight Immortals.
Why it is blocked: Though the Eight Elders were not the heads of state and were not recognized as an official body in the Constitution, major decisions had to be run through them. During the June 4 demonstrations, it was the Elders who drove Politburo discussions which eventually led to the crackdown. A new wave of elders (including Jiang Zemin) has since replaced the original eight, but they do not wield the power that the 1980s and 90s body once did. [Status - 11/17/11: blocked; 2/5/12, 3/12/12: unblocked]