Your standing in Avalon is a broad-based assessment of your progression from the "newborn" novice start (i..e. newly created character) to the higher echelons of Avalon society occupied by noble representatives of the Crown like Prince and Princess or players entrusted with a deity's entire Order (usually called High Priests).
A player's standing reflects the length of their Avalon life, time spent in Avalon, experiences and deeds witnessed or achieved and - once of senior standing - factors like high positions (e..g. being a Minister or Prince or High Priest or Guildmaster) are taken into consideration. Those of senior standing need not be too concerned about their standing since it will have very little impact on your day to day Avalon life. It is not - for instance - a factor in determining bloodlust and fight-target suitability.
In short: not something to worry about but enjoy watching it rise as your stature in the realm grows.
The first standing level, indicating not yet having graduated novicehood:
These are known as the junior standings:
1. LW-NOVICE badges to complete / prize to win
2. LW-JUNIOR basic duties OK / completing apprenticeship
3. MW-JUNIOR duties entrusted / deeds to consider / minor aideships
Here are the mid-level standings:
4. LOW-MIDDLING duties of importance / deeds of great renown / major aide
5. MIDDLING progressing well / key duties / deeds possible / junior ministries
6. HI-MIDDLING entrusted with key duties / leadership roles / ministerial or deputy/second-in-command positions
And most at length reach a senior standing:
8. SENIOR deeds by default / legendary feats to consider
9. HI-SENIOR feats to achieve / high rank held / realm-defining role
With a few earning the right to the highest standing:
= + LEGEND feats aplenty / unique significant mark on an era
= * PARADIGM paradigm status bestowed / exemplar of profession
SCORE will tell you the current standing and WHO/QW are arranged in order of an individual's standing. You can type STANDINGS to see an interesting list of everyone in current WHO list along with his or her standing and a few pertinent pieces of info about city, profession and experience level.