--- a/top/maint.mk
+++ b/top/maint.mk
@@ -126,7 +126,7 @@
 
 _cfg_mk := $(shell test -f $(srcdir)/cfg.mk && echo '$(srcdir)/cfg.mk')
 
-# Collect the names of rules starting with `sc_'.
+# Collect the names of rules starting with 'sc_'.
 syntax-check-rules := $(sort $(shell sed -n 's/^\(sc_[a-zA-Z0-9_-]*\):.*/\1/p' \
 			$(srcdir)/$(ME) $(_cfg_mk)))
 .PHONY: $(syntax-check-rules)
@@ -294,7 +294,7 @@
 	halt='found SPACE-TAB sequence; remove the SPACE'		\
 	  $(_sc_search_regexp)
 
-# Don't use *scanf or the old ato* functions in `real' code.
+# Don't use *scanf or the old ato* functions in "real" code.
 # They provide no error checking mechanism.
 # Instead, use strto* functions.
 sc_prohibit_atoi_atof:
@@ -326,15 +326,15 @@
 	  $(_sc_search_regexp)
 
 # Using EXIT_SUCCESS as the first argument to error is misleading,
-# since when that parameter is 0, error does not exit.  Use `0' instead.
+# since when that parameter is 0, error does not exit.  Use '0' instead.
 sc_error_exit_success:
 	@prohibit='error *\(EXIT_SUCCESS,'				\
 	in_vc_files='\.[chly]$$'					\
 	halt='found error (EXIT_SUCCESS'				\
 	 $(_sc_search_regexp)
 
-# `FATAL:' should be fully upper-cased in error messages
-# `WARNING:' should be fully upper-cased, or fully lower-cased
+# "FATAL:" should be fully upper-cased in error messages
+# "WARNING:" should be fully upper-cased, or fully lower-cased
 sc_error_message_warn_fatal:
 	@grep -nEA2 '[^rp]error *\(' $$($(VC_LIST_EXCEPT))		\
 	    | grep -E '"Warning|"Fatal|"fatal' &&			\
@@ -1078,15 +1078,15 @@
 
 # Sometimes it is useful to change the PATH environment variable
 # in Makefiles.  When doing so, it's better not to use the Unix-centric
-# path separator of `:', but rather the automake-provided `$(PATH_SEPARATOR)'.
-msg = '$(ME): Do not use `:'\'' above; use $$(PATH_SEPARATOR) instead'
+# path separator of ':', but rather the automake-provided '$(PATH_SEPARATOR)'.
+msg = '$(ME): Do not use '\'':'\'' above; use $$(PATH_SEPARATOR) instead'
 sc_makefile_path_separator_check:
 	@prohibit='PATH[=].*:'						\
 	in_vc_files='akefile|\.mk$$'					\
 	halt=$(msg)							\
 	  $(_sc_search_regexp)
 
-# Check that `make alpha' will not fail at the end of the process,
+# Check that 'make alpha' will not fail at the end of the process,
 # i.e., when pkg-M.N.tar.xz already exists (either in "." or in ../release)
 # and is read-only.
 writable-files:
@@ -1446,9 +1446,9 @@
 # TS-start
 
 # Most functions should have static scope.
-# Any that don't must be marked with `extern', but `main'
-# and `usage' are exceptions: they're always extern, but
-# do not need to be marked.  Symbols matching `__.*' are
+# Any that don't must be marked with 'extern', but 'main'
+# and 'usage' are exceptions: they're always extern, but
+# do not need to be marked.  Symbols matching '__.*' are
 # reserved by the compiler, so are automatically excluded below.
 _gl_TS_unmarked_extern_functions ?= main usage
 _gl_TS_function_match ?= /^(?:$(_gl_TS_extern)) +.*?(\S+) *\(/
@@ -1458,9 +1458,9 @@
 # export _gl_TS_extern = extern|XTERN
 _gl_TS_extern ?= extern
 
-# The second nm|grep checks for file-scope variables with `extern' scope.
+# The second nm|grep checks for file-scope variables with 'extern' scope.
 # Without gnulib's progname module, you might put program_name here.
-# Symbols matching `__.*' are reserved by the compiler,
+# Symbols matching '__.*' are reserved by the compiler,
 # so are automatically excluded below.
 _gl_TS_unmarked_extern_vars ?=