These shared forms were known as "conventions of expression."
In an outline, capital letters are typically followed by a period or a parenthesis. This helps to clearly identify each level of the outline hierarchy.
abbreviation
I believe you are thinking of "abbreviation".
Personal diaries and letters are very useful to historians. They help provide accurates pictures of what daily life was like in a historic period. Some diaries, such as that of Anne Frank, help people to understand from the view of the diarist, the events of their time.
Letters and diaries provide firsthand accounts and personal perspectives on historical events and everyday life, offering insights into the thoughts, feelings, and experiences of individuals from the past. This can help historians understand the human element of history and provide a more intimate view of the time period. Additionally, letters and diaries can reveal details that may not be found in official documents or other types of sources.
The period that followed extensive glaciation in the Precambrian is called the Proterozoic Eon. This period was characterized by the development of complex life forms and the formation of supercontinents.
I believe you are thinking of "abbreviation".
It is an abbreviation, one example being Dr. for a doctor.
There is no sense asking what Shakespeare's favourite anything was, since he left us no diaries or letters which would tell us. We have no idea about Shakespeare's favourites. Period.
The period in time that followed the dominance of the Minoans and Myceneans was called the Dark Ages.
The Silurian period followed the Ordovician period.
The part of a file name that determines which program to use for opening it is called the "file extension." It typically consists of a period followed by a few letters, such as ".txt" for text files or ".jpg" for image files. The operating system uses this extension to associate the file with the appropriate application.