The two dots above a letter, you mean, would be called a diaeresis and/or an umlaut.
Hold down the Alt key and type 139
It means that the "U" now says oo as in boo
The dots over i and j are called tittles. This is what wikipedia says:The tittle first appeared in Latin manuscripts in the 11th century, to distinguish the letter i from strokes of nearby letters. Although originally a larger mark, it was reduced to a dot when Roman-style typefaces were introduced.The 'u' or 'j' with two dots over are used in some languages,hungarian, Portuguese, to represent a different vowel sound to the English sound.I think they represent a vowel that is more 'fronted' than the English vowel.
What no they mean
dieresis
The two dots above a letter, you mean, would be called a diaeresis and/or an umlaut.
Depending on how it is used, a dot over a "T", used in a prescription order, could mean 1, such as 1 tablet/pill.... 1 time daily.
Do you mean, one dot above two dots? If that's what you intended, it means "therefore." I don't think ever seen two dots above one dot... wikipedia article on this: http://en.wikipedia.org/wiki/Therefore_sign
10 is two lines 11 is one dot over two lines 12 is two dots over two lines etc... 20 is one dot over a shell. 21 is one dot over one dot 22 is one dot over two dots etc... 39 is one dot over four dots over three lines 40 is two dots over a shell 41 is two dots over one dot 42 is two dots over two dots etc... 60 is three dots over a shell etc... 80 is four dots over a shell etc... 100 is a line over a shell The Mayan number system is a base-20 system. A dot is 1, a line is 5, and up to 19 you can write in one "digit". As soon as the number increases over 20, it goes up into the second "digit" and you stack a dot (this time multiplied by 20) over a shell shape (worth zero). It's just like our number system, except our number system uses a base-10 system.
When a vowel has two dots over it (diaeresis), it indicates that the vowel is to be pronounced as a separate syllable rather than combined with the previous vowel. This is common in some languages, like German and Dutch, to show that the two vowels should be pronounced individually.
I think the two dots are an umlaut. In that cas it is pronunced as if there were an e after the a. 'Staer'
Two dots over a vowel is normally called a dieresis. There is a special case of the dieresis in German where the two dots cause the vowel to change (sound and meaning): this special case is called umlaut.
3 TABLETS
It is an accent such as FARAAD
A capital A with two dots over it is typically used in news articles to indicate that the information was based on anonymous sources or is unverified. This is a common journalistic practice to protect the identity of sources or to denote that the information has not been independently confirmed.
If there is one dot over the 0 and one over the 7 then it indicates a recurring decimal. for example 6.07 with a dot over the 0 and 7 would be 6.07070707... It the two dotted numbers are further apart, the the sequence between them is repeated. For example, 6.01237 with a dot over the 0 and 7 is 6.012370123701237... But I have yet to come across a double dot over ONE number.