Some misunderstood or unknown tricks (LaTeX)

Some very simple things to do in LATEX2e are often misunderstood (or simply unknown) to the –even skilled– writer. We here present some useful codes for
1. pedagogical uses: write a matrix with borders; show simplifications of terms in mathematical developments,
2. presenting data: make an accolade in a table,
3. solving the Springer’s tocdepth problem in svmono class,
4. writing european envelopes in an efficient way,
5. improving typography: the microtype package.