Why does a gallows character start almost every page?

[pfeaster]

Or:

• Gallows specify which cipher key is to be used to decrypt the following text.
  
• Gallows serve a purpose similar to capital letters in marking whatever immediately follows as important (paragraph starts, proper names, etc.). 
  
• Gallows function like pilcrows and/or serve some other punctuation-like function.
  
• Gallows are inserted (optionally) to help the reader break text into chunks for parsing.
  
• Gallows serve some distinctive grammatical function in a constructed language.
  
• Each unit of Voynichese text within a paragraph "builds on" the preceding unit, and gallows are somehow connected with setting up a "starting point."
  
• Gallows [p] and [f] mimic majuscule characters in form and typical distribution as of the 15th century (most common at paragraph starts and in first lines of documents).