Popular transistors.

BC846A transistor.
Pinout. Datasheet.

Marking: 1B with an additional letter, or dash sign, denoting the manufacturer.For example - 1Bp and 1B-(made in Hong Kong), 1Bt(made in Malaysia),1BW(made in China).
Package: SOT-23, 1-collector, 2-emitter, 3-base.
Material of transistor: Si
Polarity: NPN
Total Devise power dissipation |PD|: 0.250 W(at ambient temperature ≤ + 25 )
Collector-base breakdown voltage |VCBO|: 80V
Collector-emitter breakdown voltage |VCEO|: 65V
Emitter-base breakdown voltage |VEBO|: 6V
Maximum collector current |Ic max|: 0.1A
Maximum junction temperature |Tj|: +150 C
Transition frequency (ft) : 100MHz(min)
Collector Capacitance|Cc|:3pF(max.)
Collector-emitter saturation voltage|VCE|:200mV(IC=100mA,IB= 5mA)
Base-emitter saturation voltage|VBE|:900mV(IC=100mA,IB=5mA)
Forward current transfer ratio |hFE| : 200-450,(IC= 2mA,VCE=5V),

BC846B Datasheet (PDF)

Table for identifying the type of SMD devices.