These are symbols that we as reviewers may supply as character entities but which we have not (yet) instructed the vendors to recognize. All symbols listed here should also be present in the basic charents file EEBOchar.ent. Some may not be 'real' symbols, i.e., they may be idiosyncratic uses by particular authors, prints, or individual books (the symbols for the exponents, for example, look suspiciously like 'hijacked' characters). Time will tell.
Note: A fairly comprehensive table of (largely) chemical symbols is available HERE in pdf form, taken from the 1702 fourth edition of The Physical Dictionary (source: ECCO)
Symbol  Meaning  Entity  Example(s)* 

Conjunction = 0° (astrology/astron.)  &conjunction;  
Note: sometimes the symbol for Mars is used for "conjunction," presumably because the printer lacks the specific conjunction sign.  
Opposition = 180° (astrology/astron.)  &opposition;  
Trine = 120° (astrology/astron. context only; cp. Greek delta, etc.)  &trine;  
This is an alternative version of trine that may be recorded as &trine2;  
Quadrine = 90° (astrology/aston. context only; may by default be captured as it appears, as □)  &quadrine  
Sextile = 60° (astrology/astron. context only; cp. Greek asterisk (*), sal amoniac symbol, etc.)  &sextile;  
Moon, full, new, or quartered (calendrical context): filledin circle usually new moon, open circle full moon but sometimes reversed. Lefthalf filled should be first quarter; righthalf filled should be third quarter.  &Moonround;  
North (or ascending) node, in astrol. context. AKA "dragon's head."  &northnode;  
South (or descending) node, in astrol. context. AKA "dragon's tail."  &southnode;  
Lacking a north/south node sign, printers will often substitute the sign fo Leo (upright or inverted as necessary). As with other typographical errors, if the book uses the wrong symbol, capture the symbol that is actually there. In this book the north and south node symbols (here with Leo standing in) are reversed. 

a 'punctus elevatus' (sometimes indistinguishable from a question markbut this is used more like a comma than like a question mark)  &punctel;  
compare this, a question mark from the same book, to the punctus elevatus above.  ?  
q 
(idiosyncratic use of q?)  <ABBR EXPAN="square">q</ABBR>  
meaning: 'circle' or ?? (entity is for all meanings of this glyph *OTHER THAN* those related to the identicalappearing entity &Sun;)  &circdot  
meaning: proportion, proportional to (other examples with different meanings should probably use simple double colon (::) or if necessary a different entity)  &proportion;  
meaning: 'difference' or '200' (entity is for for this shape of glyph, regardless of meaning)  &lazyS;  
equal sign, rare and late, and may appear with notable glyph variance  =  

root = quantity to the power of 1. Capture as the powerof1 entity regardless of the form of the glyph (there are competing forms).  &powerof1; 


quadrat or square = quantity to the power of 2. Capture as the powerof2 entity regardless of the form of the glyph (there are competing forms).  &powerof2; 


cube = quantity to the power of 3. Capture as the powerof3 entity regardless of the form of the glyph (there are competing forms).  &powerof3; 


foursquared quadrat (quadrat of quadrat) = quantity to the power of 4. Capture as the powerof4 entity regardless of the form of the glyph (there are competing forms).  &powerof4; (preferred) or &powerof2;&powerof2; 


sursolid or surd solid = quantity to the power of 5. Capture as the powerof5 entity regardless of the form of the glyph (there are competing forms).  &powerof5; (preferred) or s&powerof2; 


squared cube (quadrat of a cube) = quantity to the power of 6. Capture as the powerof6 entity regardless of the form of the glyph (there are competing forms).  &powerof6; (preferred) or &powerof2;&powerof3; 

quantity to the power of 7. Capture as the powerof7 entity regardless of the form of the glyph (there may be competing forms).  &powerof7;  
quantity to the power of 8. Capture as the powerof8 entity regardless of the form of the glyph (there may be competing forms).  &powerof8;  
quantity to the power of 9. Capture as the powerof9 entity regardless of the form of the glyph (there may be competing forms).  &powerof7;  
atypical abbreviation mark for 'qui' (this symbol can have other meanings and usually does); compare next.  &abqui; 


standard abbreviation mark for 'qui'  q^i  
[brevelike mark, usually above 't']  abbreviation mark for 'ur' (usu. in Latin passives or deponents)  &abur; 

abbreviation mark for 'ur' quare or quia.  qr (vendors) <ABBR>qr</ABBR> (reviewers, if noticed) 
See also the keyers' newcharacters table
musical sign fermata (cadence or close)  &fermata;  
musical sign fermata below (cadence or close)  &fermatab;  
musical sign C clef  &cclef;  
musical sign G clef  &gclef;  

musical sign F clef  &fclef;  
repeat or musical sign for congruence of voices or beginning of vocal part  &vocaljoin;  
musical sign large (note) or double long note or nota maxima  ¬elarge;  
musical sign long (note) or nota longa  ¬elong;  
musical sign breve or brief (note) or nota brevis  ¬ebreve;  
musical sign semibreve or semibrief (note) or nota semibrevis  ¬esemibreve;  
musical sign minim (note) or nota minima  ¬eminim;  
musical sign crotchet (note)  ¬ecrotchet;  
musical sign quaver (note)  ¬equaver;  
musical sign semiquaver (note)  ¬esemiquaver;  
musical sign demisemiquaver (note)  ¬edemisemiquaver;  
N.B. for 'augmentation dot' after notes, use simple middot entity  
musical sign direct  &direct;  
musical mensuration sign indicating time perfect (a circle) and prolation imperfect (no dot or prick) (U+1D1C8)  &timeperfprolatimperf;  
musical mensuration sign indicating time perfect (a circle) and prolation perfect (dot or prick) (U+1D1C7)  &timeperfprolatperf;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (no dot or prick) (U+1D1CB)  &timeimperfprolatimperf;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (dot or prick) (U+1D1CA)  &timeimperfprolatperf;  
musical mensuration sign indicating time perfect (a circle) and prolation imperfect (no dot or prick) with stroke indicating diminution (not in Unicode)  &timeperfprolatimperfstr;  
musical mensuration sign indicating time perfect (a circle) and prolation perfect (dot or prick) with stroke indicating diminution (not in Unicode)  &timeperfprolatperfstr;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (no dot or prick) with stroke indicating diminution (U+1D1CD)  &timeimperfprolatimperfstr;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (dot or prick) with stroke indicating diminution (not in Unicode)  &timeimperfprolatperfstr;  
musical mensuration sign indicating time perfect (a circle) and prolation imperfect (no dot or prick) with cross indicating double diminution (not in Unicode)  &timeperfprolatimperfx;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (no dot or prick) with cross indicating double diminution (not in Unicode)  &timeimperfprolatimperfx;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (no dot or prick) reversed to indicate diminution (U+1D1CC)  &timeimperfprolatimperrev;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (dot or prick) reversed to indicate diminution (not in Unicode)  &timeimperfprolatperfrev;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (no dot or prick) reversed and with a stroke to indicate double diminution (U+1D1CE)  &timeimperfprolatimperfrevstr;  
musical mensuration sign indicating time imperfect (a cshaped broken circle) and prolation imperfect (dot or prick) reversed and with a stroke to indicate double diminution (not in Unicode)  &timeimperfprolatperfrevstr;  
Note: when these symbols are accompanied by numbers, treat the numbers as one normally does; e.g. a subscripted number should be captured using ^^.  &timeperfprolatimperf;2 &timeimperfprolatimperf;2 &timeperfprolatperf;2 &timeimperfprolatperf;2. &timeimperfprolatperf;^^3 &timeperfprolatperf; 3 

musical barline (U+1D100)  &barline;  
musical double barline (U+1D101)  &Barline; 
The following is at this point more an informationgathering exercise than a finished set of symbols and capture instructions. Feel free to supply more and better examples.
Symbol  Meaning  Capture  Context 

Musical rest (value of large note)  &restlarge;  
Musical rest (value of long note)  &restlong;  
Musical rest (value of breve note)  &restbreve;  
;  Musical rest (value of semibreve note)  &restsemibreve;  
Musical rest (value of minim note)  &restminim;  
Musical rest (value of crotchet note)  &restcrotchet;  
Musical rest (value of quaver note)  &restquaver;  
Musical rest (value of semiquaver note)  &restsemiquaver; 
mathematical sign for lower or graver than (open triangle pointing down) [perhaps unique to Wd1132]  &lowerthan;  
mathematical sign for lower or graver term [perhaps unique to Wd1132]  &lowerterm;  
mathematical sign for higher of more acute than [perhaps unique to Wd1132]  &higherthan;  
mathematical sign for higher of more acute term [perhaps unique to Wd1132]  &higherterm;  
mathematical sign for continued proportion [perhaps unique to Wd1132]  &proportion2;  
mathematical sign for ratio (special use of Rx symbol) [perhaps unique to Wd1132]  &ration;  
mathematical sign for logarithm [perhaps unique to Wd1132]  &logarithm;  
mathematical sign for divisor or divided by (formally identical to eccentric greater than sign (entity morethan) [perhaps unique to Wd1132]  &divisor;  
mathematical sign for quotient (resembles divisor with slight hook) [perhaps unique to Wd1132]  "ient;  
mathematical sign for multiplier or multiplied by (resembles m followed by tilde) [perhaps unique to Wd1132]  &multiplier;  
mathematical sign for multiplication product (resembles m with superscripted i or acute) [perhaps unique to Wd1132]  &product;  
mathematical sign for potestas or power (perhaps a form of powerof1 entity) [perhaps unique to Wd1132]  &potestas;  
mathematical sign for sum [perhaps unique to Wd1132]  Z  
mathematical signs for excess or difference [perhaps unique to Wd1132] (either X or subscripted x)  X or ^^x  
Lshaped decimal separator (functions like decimal point; may extend under numbers to its right.)  &decimalL; (with no spaces around it, e.g. "1&decimalL;8" which means "1.8") 

* examples taken from Wc785 and Wp2506; sextile taken from Wc7525; north node from Wf622. Alternative versions of trine, opposition, and conjunction are from S5802, as are the reversed versions of dragon's head and dragon's tail. Math(s) symbols from Wm1484 (vid30766/83) and Wd1132 (vid58581/39); music from Wn1058 (vid64961), Wd1132 (vid58581/39), and S18132 (vid 12119, around image 11)
* examples from VID 152131, image 640; and VID 110567 (Edward Bernard's alphabet chart).
asterisk used by Origen as critical siglum, alternating with obelus.  &asterisc; 


obelus or obelisk used by Origen as critical siglum, alternating with asterisk. Divisionlike mark is commonest form.  &obelus;  
the twodotted 'ribbon' ('lemnisc') form of obelus.  &lemnisc;  
the singledotted 'ribbon' ('lemnisc') form of obelus with the dot below.  &hypolemnisc;  
the singledotted 'ribbon' ('lemnisc') form of obelus with the dot above.  &hyperlemnisc;  [may not be attested.]  

Some examples from modern treatment, Anecdotum Romanum de notis veterum criticis inprimis Aristarchi Homericis et Iliade Heliconia edidit .. Fridericus Osannus (Gissae, 1851)
repeat preceding strain.  &dncrepeat;  
or 
repeat preceding strain twice.  &dncrepeat2;  
repeat preceding strain thrice.  &dncrepeat3;  
repeat entire tune. (?)  &dncstartover;  
(sun sign)  male dancer  &dncmale;  
(moon sign)  female dancer  &dncfeale; 