elf(5): Further details on Notes

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man5/elf.5

@@ -1846,11 +1846,11 @@ This is automatically populated by the linker.
 ELF notes allow for appending arbitrary information for the system to use.
 They are largely used by core files
 .RI ( e_type
-o f
+of
 .BR ET_CORE ),
 but many projects define their own set of extensions.
 For example,
-the GNU tool chain uses ELF notes to information from
+the GNU tool chain uses ELF notes to pass information from
 the linker to the C library.
 
 Note sections contain a series of notes (see the
@@ -1893,7 +1893,12 @@ Keep in mind that the interpretation of
 depends on the namespace defined by the
 .I n_namesz
 field.
-After, of course, having determined whether the ELF image is a core file.
+If the
+.I n_namesz
+field is not set (e.g., is 0), then there are two sets of notes:
+one for core files and one for all other ELF types.
+If the namespace is unknown, then tools will usually fallback to these sets
+of notes as well.
 .in +4n
 .nf
 
@@ -1936,6 +1941,9 @@ following values:
 Notes used by all core files.
 These are highly operating system or architecture specific and often require
 close coordination with kernels, C libraries, and debuggers.
+These are used when the namespace is the default (i.e.,
+.B n_namesz
+will be set to 0), or a fallback when the namespace is unknown.
 .RS
 .TP 21
 .PD 0
@@ -2109,11 +2117,10 @@ The desc consists of any nonzero number of bytes.
 The desc contains the GNU Gold linker version used.
 .RE
 .TP
-.B Unknown system
-The fallback set of note types when the namespace is unknown.
-Usually the name field will be omitted (i.e.,
+.B Default/unknown namespace (e_type != ET_CORE)
+These are used when the namespace is the default (i.e.,
 .B n_namesz
-will be set to 0).
+will be set to 0), or a fallback when the namespace is unknown.
 .RS
 .TP 21
 .PD 0