By Matt Holder
Eta has used a range of tactics including killings and car bombs
Why does the BBC call Eta "Basque separatists" and not terrorists?
It's a question that gets asked every time the group stages another attack in its campaign to form an independent Basque homeland.
And the BBC's policy not to call Eta (short for Euskadi Ta Azkatasuna) terrorists often prompts angry calls and letters from viewers and listeners in the UK and abroad.
After all, if the Spanish government refers to them as a "terrorist group", why shouldn't the BBC?
Some viewers claim that by not using the terrorist tag, and using separatist instead, it gives legitimacy to the group's cause.
Others claim terrorism is the only way to adequately describe a bloody campaign for independence that has led to more than 800 deaths over the last 30 years.
The use of language in reporting atrocities is something to which the BBC gives a great deal of thought.
It avoids labels wherever it can. And its credibility is severely undermined if international audiences think they can detect a bias for or against any of those involved.
As part of the BBC's duty to be impartial, independent and accurate, it tries to use neutral and factual language wherever possible.
The words terrorist and terrorism when applied to a specific group are subjective and can carry a sense of condemnation.
"Basque separatist" is a factual explanation of the group and its goals.
Its tactics and operations are made clear by the context of the stories themselves.
General use of the words terror and terrorism are not banned, it's simply a case of common sense how and when they are used.
For instance, they can be used in a non-specific context as well as in direct quotes.
An on-screen graphic on News 24 or a headline on the News website might read "Airlines on terror alert" or "Police conference on terrorism".
And world leaders might condemn specific groups as terrorists but if the BBC carries their quotes, it will clearly attribute those remarks.