Meanings of lower case letter in English

The new planet was detected around Alpha Centauri B, and exoplanets are given a lower case letter starting with b.

A password containing six lower case letters takes just a fraction of a second to crack.

This new imprint is in capitals and lower case letters on a colored strip 56 mm.

Lower case letters (a-d) indicate ancestral character states, and upper case letters (A-D) indicate derived character states.

This approach may not provide the best possible passwords, which should ideally include capital as well as lower case letters, and one or more numbers.

If you have an 8 character password with just lower case letters, that would give 268 = 2 x 1011 combinations.