Downton Abbey is back with a bang and for a series set almost 100 years ago, some of its themes are surprisingly relevant today.
Yes, we're talking etiquette.
While Lady Mary negotiates the shifting conventions of 1920s Britain (good gracious, did she just refuse to side saddle her horse?), we're muddling through the dos and don'ts of Tinder while trying to fathom who should pay in a world where women sometimes earn more than men.
To figure out the "correct" way to behave in 2015, we've enlisted the help of Debrett's - the "trusted source on British social skills, etiquette and style".
They talk us through everything from whether or not you should add your co-workers on Facebook to when you're required to leave a tip.
Although as Lady Mary has proven, sometimes it's fun to bend the rules just a little...
Should you add work colleagues on Facebook?
It’s fine to add work colleagues on Facebook if you would socialise with them outside of the office – just be aware that in doing so you are sharing personal information with them, so avoid any work-related rants.
If you wouldn’t dream of going for a drink with someone outside of the office, it’s best not to open your life up to them via Facebook.
When and where is it acceptable to use E-cigarettes?
In the UK, it is currently legal to use e-cigarettes in public spaces (with certain exclusions, such as on public transport in London). Wherever you are, however, it is best to consider those around you and to ask the permission of your host, companions or colleagues beforehand.
Is it acceptable to do your make-up on public transport?
A discreet application of lipstick or touch-up of mascara is fine, but applying full make-up in transit may annoy your fellow passengers.
Avoid the hazards of jerky tubes and dimly-lit trains by sticking with the bathroom mirror where possible.
Who should pay on a first date?
It is usual for the person who has issued an invitation to pay, but if an invitee wishes to contribute they may offer to split the bill, buy a round of drinks or perhaps suggest a second date in return.
Is it ever okay to have your phone out at the dinner table?
Mobiles should be put away at the dining table (whether at home or eating out), and calls should only be taken, away from the table, in exceptional circumstances.
Instigating a light-hearted, mutual ‘no phone policy’ at the beginning of a meal may ensure your friends stick to this rule and give you their full attention.
Is it okay to eat on public transport?
Eating in a confined space such as a tube or train carriage can offend others and is best avoided if possible.
If it’s essential to grab a bite to eat while on the move, choose food that doesn't smell and won’t make a mess – and remember to take any rubbish with you.
If you go to a restaurant with a group of friends, should you split the bill equally, or pay for what you ate?
It’s best to agree a policy from the outset, such as sticking to a set menu or only having one course. The usual approach is to divide the bill equally at the end and not to argue about what any one person has ordered.
However, those who order very expensive dishes with supplements, or additional wine or after-dinner drinks, should offer to pay extra.
Where should you leave a tip?
It is traditional to leave 10% in restaurants, but up to 15% is now commonplace for good service. Many restaurants now include a service charge in the bill, in which case a tip is not necessary other than for exceptional service.
It is also traditional to tip taxi drivers 10%. Tips are not necessary when just drinking in pubs, but bar staff who have been particularly helpful may be bought a drink.