You create a text file with, say, Notepad and save it with an extension of .txt The text is made up of words and, possibly, references. You can decide which symbols are to be treated as letters, a word being defined as a series of one or more letters. A reference is a special symbol say < followed by a conventional letter, a space, and say a > symbol. For example <A Lincoln> which might mean Author Lincoln. When a reference letter of L is used only figures are allowed say <L 200> indicating line 200.
When you use Microsoft Word to create a document you should save it as a 'TextFile with line breaks' and use the .txt extension. If you were to choose the SaveAs option to a TextFile without line breaks then each paragraph would appear to SCP as 'one line' ; thus the line based operations in SCP would become paragraph operations.