Just an addition to Heiko's good answer.
In the case of the warning message
Missing character: There is no ▒ in font cmr7!
you get when some 8 bit character is used and
inputenc with a suitable option is not loaded, the warning is not related to
Indeed, with this simple input (say it's Latin-1 encoded, I add the proper magic line for Emacs)
% -*- coding: latin-1 -*-
you wouldn't get any warning of missing character, as the following excerpt of the
.log file shows:
This is pdfTeX, Version 3.1415926-2.4-1.40.13 (TeX Live 2012) (format=pdflatex 2012.10.11) 18 OCT 2012 22:40
entering extended mode
restricted \write18 enabled.
%&-line parsing enabled.
Babel <v3.8m> and hyphenation patterns for english,
LaTeX Font Info: Checking defaults for U/cmr/m/n on input line 4.
LaTeX Font Info: ... okay on input line 4.
Here is how much of TeX's memory you used:
410 strings out of 493488
3732 string characters out of 3141325
49432 words of memory out of 3000000
3798 multiletter control sequences out of 15000+200000
4403 words of font info for 15 fonts, out of 3000000 for 9000
957 hyphenation exceptions out of 8191
23i,4n,17p,160b,113s stack positions out of 5000i,500n,10000p,200000b,50000s
Output written on mohan.pdf (1 page, 11830 bytes).
13 PDF objects out of 1000 (max. 8388607)
8 compressed objects within 1 object stream
0 named destinations out of 1000 (max. 500000)
1 words of extra memory for PDF output out of 10000 (max. 10000000)
However the output would probably be unexpected, as it would show
This is because the T1 encoded font that has been used has
SS in the slot where Latin-1 has
Therefore the warning has nothing to do with
inputenc, but it's rather generated in your case by the fact that the font you're using has only 128 characters rather than the 256 of the T1 encoded font in my example. The warning is related to output and not to input.