You're asking about two of the four Cs in diamond grading: clarity and colour.
Clarity
The numbers are self-explanatory. The initials are:
You can read more, below.
Colour
The colours you list are in the second tier of desirable colours for 'colourless' diamonds, D through H, being the most desirable.
You can read more, below.
it means that a porfecinal has authenticated and determaned the codition of a coin
PR is a grading system used for proof coins
DCAM stands for Deep Cameo and is reserved for proof coins
PQ= Premium Quality. Bu= Brilliant Uncirculated.
It means "premium quality". It is not an official form of grading.
In grading a diamond's clarity, VS indicates Very Slight.
H1 is not a common notation for describing a diamond. H is one description for a colour. Numbers usually follow V, VV, or VVS; S, SI and so forth, indicating the number of visible flaws in a stone. H1, then, may be a typo in a description.
The full form of vs is very slight.You can read more about GIA clarity grading systems, below, which include the vs assignment in context.
Clarity H-I sounds more like the colour grade. Clarity I2-i3 means that there are two or three visible inclusions in the diamond. This is the lowest clarity grade for gem-stone quality diamonds.
If by 'you' you mean 'U', and you're query is about clarity and not colour, it is possible that 'U' indicates unenhanced. Unenhanced diamonds are more valuable than enhanced diamonds.
The indicator E-F in diamond grading may indicate a colour range for a white diamond. It is in the most desirable range, also known as colourless. You can review the colour range, below.
One can assume that clarity I2 is what you mean, instead of 12 -- 'eye two' not 'one two'. A diamond with clarity I2 means that there are multiple inclusions or flaws that are visible to the naked -- unmagnified -- eye. The I stands for Included and the number represents the degree to which is it included. I1 being the least to I3 being the most.
Proof
MS66 is a grading designation used primarily for coins, indicating a high level of quality and preservation. However, when referenced in jewelry, it may denote the quality of gemstones or materials used, suggesting that they are of excellent clarity and minimal imperfections. The "MS" typically stands for "Mint State," while the number reflects the specific grading within that category. Always check the context to ensure the grading applies appropriately to the jewelry in question.
when you are grading you can use the mean as an average.
Mint status
In jewelry, "f8" typically refers to a specific quality or grading system related to gemstones, particularly diamonds. The "f" often stands for "fine," indicating a high level of clarity or quality, while the "8" could represent a particular grade on a scale. However, it's important to note that grading systems can vary, so the exact meaning may depend on the context or the jeweler's specific classification. Always check with the jeweler for clarification on their grading terms.