Secrets of Orchestral Musicians (Western classical music)

I wonder how many non-musicians or even musicians themselves know the following about orchestral musicians:

1. They bring pencils to every rehearsal and mark up their sheet music. One reason is for the "secret tablature" (below). Another is to highlight codas, repeats, etc.

2. They practice alongside recordings. So, jamming with CDs and other audio media isn't limited to rock and jazz players after all. I record rehearsals and music lessons onto my PDA. The PDA records the audio, as a WAV file, onto an SD card using Personal Audio Recorder Pro software. I then transfer the WAV file into my computer via a USB card reader.

3. Violinists, violists, and cellists have a tablature system. Even though there are no frets, there is still a mental mapping of notes to fingers and positions on the neck. Now, nobody, as far as I know, ever gives Western classical sheet music to a string player in tablature. However, chances are the string player will, when given a chance, start marking notes on the sheet music with tablature numbers. Arabic numerals are used for the finger number (1 for index finger, 2 for middle finger, etc.) and Roman numerals are used for position number. I am not yet aware of this tablature system being described in any book. It seems to be passed on by word of mouth.

I cannot imagine living without these secret techniques, especially as a beginner level violist who is frequently thrust into challenging situations beyond my skill level (such as preparing at least 1 hours worth of selections from Handel's Messiah).