Vinyl records grading scale


I am sort of new to vinyl and am building up my LP collection. A very prime source for it is the internet used market where appears to be sort of a grading scale system to rate condition of vinyl records on sale (G+-, VG+-, EXC, NM, etc). Is there any place I can refer to for the criteria or guidelines as to what to expect from the different ratings?
Also, what has been your experience buying used, and what is the lowest acceptable rating to get substantially noise free (tic/pops) records? Please let me know, thanks.
jmr
Here is a start.

Remember however, that any grading scale, whether it be the Goldmine or AudiogoN, is open to different interpretations by different individuals.

John
for the most part, records are graded visually by collectors. a visual nm which is under m- or m is as low as you really need to go. its a crapshoot.
The generally recognized grading scale was established by Goldmine and a complete version of it can be found at the link below. According to that scale a grade of VG+ for the vinyl, as opposed to the cover, would meet your listening criteria. However, my experience in buying many records in auctions is that most records which are graded VG+ by sellers in fact are overgraded and do have playback issues. There even are many sellers out there, including some with great feedback records, who grade records as mint- or near mint which still have audible problems. The bottom line is that you have to know your seller in order to know what you are getting. The only caveat to that is that the risk is a bit lower for 80's/90's pressings of common records.

http://www.recordcollectorsguild.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=17&page=1
" substantially noise free (tic/pops) records? "
Regardless of the best rating, Some albums you will find good, but mostly will have this Tic/Pop regardless unless you use a powerful vacuume based album cleaner... They can turn mud into a gem if you know what your doing.. and if you want to get serious on really good vinyl, this is your best tool to buy, although somewhat expensive to implement on the starting gate.
Guys, thanks very much for your quick responses. John/Arahl thanks for the links to the grading scale. That is exactly what I was hoping to find so that I can have an Idea of what each grade should represent.
I am very aware of the necesarily subjective nature of this process and the fact that most gradings will be a bit overstated. I am sure I will develope a feel for them after a few purchases I just want to narrow down the learning curve in terms not getting to many really bad ones.
My main concern is really noise when playing them more than visual marks wich in many ocassions do not affect playback.
Yeah, I put on my analog rig a Loricraft since inception which I consider mandatory some kind of decent RCM.
Any other comments with respect to cutt-off point for records from your experiences; or any other savy advices?
Thanks...