<a> accent
<ac> accent component
<ar> array (matrix)
<arc> array column
<arr> array row
<atop>\atop -- obsolete (replaced by <stk>)
<b> bold
<
bg> bold Greek
<case> individual case inside \cases <cases> \cases
construct <ceqn> centered equation -- obsolete
<cp> centered post -- element of <fen> -- singleton
<de> denominator of fraction
<dsty> \displaystyle --obsolete <eqaln> internal \eqalign
(aligned equation) <eqline> individual line inside
\eqalign
<f> in-line equation
<fd> display equation
<fen> fence (paired delimiter)
<fl> formula line (lines inside equation)
<fr> fraction
<g> greek
<ge> German
<hsp> horizontal space -- singleton tag
<ig> italic Greek
<in> integral
<inc> obsolete
<inf> inferior (subscript)
<it> italic
<lim> general large operator
<ll> lower limit (subscript of large operator)
<lyr> layer -- component of <stk>
<mit> math italic
<nu> numerator of fraction
<op> operator -- component of <lim>
<opd> operand -- component of <lim>
<ovb> overbrace (invented)
<ovl> overline
<phr> phrase
<pr> product
<rad> radical
<rcd> radicand -- component of radical
<rdx> radical index -- component of radical
<rf> roman function (like sin, cos)
<rm> roman <rp> right post -- component of
<fen>
<sc> script (calligraphic)
<sssty> \scriptscriptstyle -- obsolete
<ssty> \scriptstyle -- obsolete
<stk> stack (\atop)
<sum> summation
<sup> superior (superscript)
<tex> tex input -- obsolete
<tsty> \textstyle -- obsolete
<ty> typewriter type (computer font)
<ul> upper limit -- component of <lim>
<unb> underbrace (invented)
<unl> underline
<vmk> vertical mark -- used inside <fl> -- singleton
<vmkr> vertical mark reference -- also used inside <fl>
-- singleton