Definition from Wiktionary, the free dictionary
ct lower case
- Ligature of the lower‐case letters c and t. A round, leftward line from the up‐most tip of t is drawn onto the upper end of c, joining the letters.
Usage notes 
- Unicode has never officially encoded this ligature, since it is merely non‐structural, but some custom fonts support it on the code point EEC5, because of a recommendation by the Medieval Unicode Font Initiative.
- ^ http://unicode.org/faq/ligature_digraph.html#Lig3
- ^ http://www.mufi.info/specs/MUFI-Alphabetic-2-0.pdf see page 27