Panel: TEPCO chief said not use word "meltdown"

On March 14, during a press conference, a TEPCO employee handed a memo to the vice president, indicating instructions from the government not to use certain terms. This directive was reiterated multiple times, emphasizing the importance of adhering to the language guidelines provided by the government.

What was the date of the press conference mentioned in the text?

What was the significance of the memo mentioned in the text?