Is a RM8 gedcom a compressed file?
No, it is just a formatted text file.
Google questions like this for immediate and detailed answers
A gedcom is a specific formatted file using established parameters. To call it a formatted text file is not really answering my question. Is the RM8 gedcom in accordance with established gedcom guidelines and is it compressed?
The reason for asking the question is because I was asked that question from a person living in Europe. I am having a difficult time uploading a gedcom to Geneanet. So instead of googling it I went straight to the horses mouth.
Your question was clearly answered. Open a .ged with a text editor.
Actually it answered the question you asked quite well. the answer to the question you asked is no, it is not compressed. It is a plain text file formatted to the GED 5.5.X standard. There is a later GED 7 standard but no major program has implemented it as of yet. As @Rooty said, Google would have given you an immediate answer. If you want an answer ‘from the horse’s mouth’ you should have emailed RM support. They aren’t going to answer your question here since it has already be answered.