May and Shall
Union of India & Ors. vs. A.K. Pandey, (2009) 10 SCC 552
" 15. The principle seems to be fairly well settled that The Court has to examine carefully the purpose of such provision and the consequences that may follow from non-observance thereof. If the context does not show nor demands otherwise, the text of a statutory provision couched in a negative form ordinarily has to be read in the form of command. When the word "shall" is followed by prohibitive or negative words, the legislative intention of making the provision absolute, peremptory and imperative becomes loud and clear and ordinarily has to be inferred as such...................."