Outsiders who walk into a UN climate conference often experience a "beam-me-up-Scotty" moment.
Like Star Trek's Captain Kirk, they find themselves in a alien world where the people speak "Climate", a language as unsettling as Klingon... and nearly as impenetrable.
Veteran speakers know a BINGO from a TUNGO. An ENGO from a YOUNGO. A NAMA from a NAPA. A COP from a MOP.
They read "non-papers" about hot air, and talk wistfully about the days of the QUELRO. And they understand that Bottom Up versus Top Down is not smut -- it's about alternative approaches to climate policy.
A new six-day round of negotiations opened in Geneva on Sunday, a stepping stone to a conference in Paris in December where a post-2020 deal must to be sealed.
Here's a primer on what negotiators are saying:
ADAPTATION: Measures to help cope with climate impacts, such as building reservoirs as a defence against drought or sowing crops resistant to higher temperatures.
ANNEX I & ANNEX II: A division between rich and developing countries enshrined at the founding of the UNFCCC in 1992. The two lists define burden-sharing on climate change, with most responsibility on Annex I nations.
AOSIS: Association of Small Island States (AOSIS) highly vulnerable to sea-level rise.
AR5: The newly published Fifth Assessment Report of the UN's Intergovernmental Panel on Climate Change (IPCC), the top expert authority on global warming and its impacts.
BAU: Business as usual. Used for projections of global warming based on current carbon emission trajectories.
BASICs: Bloc comprising Brazil, South Africa, India, China.
BINGOs: Business and industry non-governmental organisations. ENGOs, TUNGOs and YOUNGOs are environment, trade union and youth NGOs.
BOTTOM-UP/TOP-DOWN: Bottom-up means non-binding, voluntary targets on emissions cuts. Top-down means a global target divided among parties who sign up to binding commitments -- the now unpopular approach used under the Kyoto Protocol.
CAP AND TRADE: Buying and selling unused carbon emissions quotas under a cap, or ceiling, imposed on a country, region or industrial sector.
CARBON INTENSITY: How much fossil fuel you burn to produce an economic unit -- in other words, a measure of energy efficiency. Used by China to define its action on carbon.
CBDR-RC: Common but differentiated responsibility and respective capabilities, a phrase enshrined at the founding of the UNFCCC. It means countries should fight climate change on the basis of their individual circumstances, wealth and other resources -- a thorny issue today as China, Brazil and India are now huge carbon emitters.
CCS: Carbon capture and storage, a fledgling technology to siphon and store carbon dioxide from power plants to stop it adding to the greenhouse effect.
COP: Conference of Parties, the supreme body of the UN Framework Convention on Climate Change (UNFCCC). The November 30-December 11 meeting in Paris will be COP 21.
GCF: Green Climate Fund (GCF), designed to channel potentially hundreds of billions of dollars in climate aid to poor countries.
GHGs: Greenhouse gases
G77 AND CHINA:  Gathers developing countries -- 134 in all -- which negotiates as a bloc in the climate talks. It is also divided into sub-groups along the lines of their differing interests.
HOT AIR: Surplus of greenhouse-gas quotas developed countries were allotted under the Kyoto Protocol.
INDCs: Intended Nationally Determined Contributions. Voluntary emissions-curbing pledges that must be put forward this year to provide the backbone of the 2020 climate deal.
KP: Kyoto Protocol, the 1997 accord on carbon emissions that will be superseded by the 2020 deal.
LDCs: Least Developed Countries.
LMDCs: Like-Minded Developing Countries.
LULUCF: Land Use, Land-Use Change and Forestry. A KP provision to count trees as "sinks" which absorb carbon dioxide, a hugely vexatious issue.
MITIGATION: Measures to reduce or slow emissions of greenhouse gases.
MOP: Meeting of Parties under the Kyoto Protocol.
MRV: Measurement, reporting and verification. A benchmark of transparency for.
NAMAs and NAPAs: Nationally Appropriate Mitigation Action and National Adaptation Programmes for Action. Initiatives to help LDCs ease carbon emissions or strengthen climate defences.
NON-PAPER: An informal document used to float possibly controversial ideas.
QUELRO: Quantified Emission Limitation and Reduction Obligation. A pre-INDC carbon pledge.
REDD: A forest programme (Reducing Emissions from Deforestation and Degradation).