Hello I want to know whats mean (trace) cotrace matrix.
In the context, mapping a matrix (t x n) $\in$ GF($2^m$) to a cotrace matrix (tm x n) $\in$ GF($2$)?
Hello I want to know whats mean (trace) cotrace matrix. In the context, mapping a matrix (t x n) $\in$ GF($2^m$) to a cotrace matrix (tm x n) $\in$ GF($2$)? 


I guess you mean trace paritycheck matrix and cotrace paritycheck matrix, as defined in the context of errorcorrecting codes, see definition 6 of Compact McEliece Keys from Goppa Codes, or see page 2 of arXiv:1302.5081. 

