The following are stories and questions about them. Each story is followed by a question and answer to a given question.

Story: The terms upper case and lower case can be written as two consecutive words, connected with a hyphen (upper-case and lower-case), or as a single word (uppercase and lowercase). These terms originated from the common layouts of the shallow drawers called type cases used to hold the movable type for letterpress printing. Traditionally, the capital letters were stored in a separate case that was located above the case that held the small letters, and the name proved easy to remember since capital letters are taller. 

The convention followed by many British publishers (including scientific publishers, like Nature, magazines, like The Economist and New Scientist, and newspapers, like The Guardian and The Times) and U.S. newspapers is to use sentence-style capitalisation in headlines, where capitalisation follows the same rules that apply for sentences. This convention is usually called sentence case. It may also be applied to publication titles, especially in bibliographic references and library catalogues. Examples of global publishers whose English-language house styles prescribe sentence-case titles and headings include the International Organization for Standardization.

Question: Is sentence case a requirement or a convention?
Answer:Convention

Question: What titles might it be applied to?
Answer:Publication

Question: Especially in which type of references?
Answer:Bibliographic references

Question: And also, what type of catalogues?
Answer:library catalogues.

Question: What organization does ISO stand for?
Answer:International Organization for Standardization.

Question: Are they a global publisher?
Answer:Yes

Question: Do they have an English language house style?
Answer:Yes

Question: What must their titles and headings use?
Answer:Sentence-case

Question: How many words can the terms upper and lower case be written as?
Answer:Twi

Question: What can they be connected with?
Answer:A hyphen

Question: Were the drawers deep?
Answer:No

Question: What was stored in the drawers?
Answer:Movable type for letterpress printing

Question: What were they called?
Answer:unknown

Question: Were capital letters stored in the same type case?
Answer:
No