unknown unknown

неизвестное неизвестное (But there are also unknown unknowns -- the ones we don't know we don't know (Donald Rumsfeld) MichaelBurov)

unknown unknown

: 545 phrases in 83 subjects

Automated equipment	4
Aviation	11
Biology	1
Bookish / literary	1
Business	1
Cardiology	2
Cartography	2
Chemical industry	1
Chemistry	10
Chess	2
Chromatography	7
Combustion gas turbines	1
Computer networks	4
Computers	1
Construction	3
Cryptography	2
Dialectal	1
Diplomacy	1
Drug-related slang	1
Economics	1
Electronics	8
Equestrian sports	1
Esoterics	1
European Union	1
Figurative	2
Figure of speech	1
Firefighting and fire-control systems	1
Food service and catering	1
General	136
Geology	1
Geophysics	1
Historical	1
Idiomatic	6
Informal	2
Information security and data protection	3
Information technology	30
Internet	1
Law	8
Librarianship	5
Linguistics	5
Logistics	1
Makarov	44
Mass media	2
Mathematics	43
Mechanics	5
Medical	30
Meteorology	5
Metrology	3
Microelectronics	1
Microsoft	12
Military	10
Molecular genetics	1
Music	1
Nanotechnology	1
Obsolete / dated	2
Oil / petroleum	2
Oncology	10
Operation systems	1
Ornithology	1
Patents	2
Pharmacology	2
Physics	3
Poetic	2
Politics	1
Production	3
Programming	28
Proverb	4
Psychology	5
Quality control and standards	2
Quotes and aphorisms	5
Radioengineering	1
Rhetoric	8
Robotics	1
Sakhalin	1
Scientific	2
Security systems	4
Slang	1
Software	1
Sports	1
Statistics	1
Technology	12
Telecommunications	6
Travel	2