Maturity Level

Foreword
This article was written by me for clarification. I have not been with CIVITAI long enough to really be familiar with all the features here. One of the things I have been looking for all along is information about the so-called maturity level. This information is required whenever something is published.
Maturity Level
Following the reference [2], the maturity level defined by CIVITAI is specified as follows:
PG: Safe for work; view anywhere, with anyone.
PG13: Little racier; includes revealing clothing and light blood/gore.
R: Getting risque; adult themes and situation, partial nudity, graphic violence.
X: Spicy; graphic nudity, adult objects and settings.
XXX: Avert thine eyes; Graphic sexual content, disturbing concepts and themes.
See also [1] with respect to the above list. So far General Audiences or No restrictions as rating is missing in the list.
Side Note
The rating system valid for the United States can be found in [4, 5, 6]. A comparison of the rating system world wide is given in [3].
In some countries in the world inclusive the United States General Audiences is equivalent to Parental Guidance [3].
According to my previous assessment I need most of the time PG as maturity level setting. Maybe I need in the future another one too.
Topic Related Abbreviations
The explanation of the abbreviations bases on a analysis of the world wide rating rules from [3]. I have not yet found a source for the exact definition according to CIVITAI. Accordingly, the information should be evaluated with caution.
PG → Parental Guidance Suggested
PG13 → Parental Guidance 13, Parents Strongly Cautioned (age of 13 upwards)
R → Restricted (age of 16 upwards)
X → Restricted below 18, for adults only
XXX → Explicit content (not suitable for people of a age under 18)
Other Abbreviations
Some other abbreviation with respect to the topic can be found here.
MPAA → Motion Picture Association of America
G → General Audiences
NC-17 → No Children under 17
Reference
[1] https://education.civitai.com/civitais-guide-to-content-levels/
[2] https://www.reddit.com/r/civitai/comments/1boivn0/new_content_rating_system/
[3] https://en.wikipedia.org/wiki/Motion_picture_content_rating_system
[4] https://en.wikipedia.org/wiki/Motion_Picture_Association_film_rating_system
[5] https://www.motionpictures.org/film-ratings/
[6] https://www.filmratings.com/RatingsGuide
Finally
Have a nice day. Have fun. Be inspired!