$ grep -r "a-z" src/
src/plugins/zandronum/zandronumserver.cpp:const QRegExp ZandronumVersion::versionExpression(R"((\d+).(\d+)(?:.(\d+)(?:.(\d+))?)?(?:-([a-zA-Z]*)?)?(?:-r(\d+)(?:-(\d+))?)?)");

src/plugins/zandronum/zandronumrconprotocol.cpp:        static const QRegExp colorCode(R"(\\c(\[[a-zA-Z0-9]*\]|[a-v+\-!*]))");

src/core/gui/widgets/serverconsole.cpp:         static const QRegExp colorCode("\034(\\[[a-zA-Z0-9]*\\]|[a-v+\\-!*])");

src/core/irc/ircnicknamecompleter.cpp:          const QString NICKNAME_MATCH = R"(\[\]\{\}\-\^\`\|\\A-Za-z0-9_)";

src/core/commandline.cpp:       QRegExp reallySafestCharsIHope = QRegExp("[^a-z0-9/\\_-+]", 
Qt::CaseInsensitive);
src/core/serverapi/serverstructs.cpp:   return name.toLower().remove(QRegExp("[^a-z0-9]"));

$ grep -r '\\\"' src/ | wc -l
127