These
.Dq blocks
are always a multiple of the record size.
-The most common block size\(emand the maximum supported by historic
-implementations\(emis 10240 bytes or 20 records.
+The maximum block size supported by early
+implementations was 10240 bytes or 20 records.
+This is still the default for most implementations
+although block sizes of 1MiB (2048 records) or larger are
+commonly used with modern high-speed tape drives.
(Note: the terms
.Dq block
and
the system.
.It Va devmajor , Va devminor
Major and minor numbers for character device or block device entry.
-.It Va prefix
-First part of pathname.
+.It Va name , Va prefix
If the pathname is too long to fit in the 100 bytes provided by the standard
format, it can be split at any
.Pa /
-character with the first portion going here.
+character with the first portion going into the prefix field.
If the prefix field is not empty, the reader will prepend
the prefix value and a
.Pa /
character to the regular name field to obtain the full pathname.
+The standard does not require a trailing
+.Pa /
+character on directory names, though most implementations still
+include this for compatibility reasons.
.El
.Pp
Note that all unused bytes must be set to
happens to have a
.Pa /
as the 156th character.)
-POSIX requires numeric fields to be zero-padded in the front, and allows
+POSIX requires numeric fields to be zero-padded in the front, and requires
them to be terminated with either space or
.Dv NUL
characters.
.Nm pdtar
public-domain implementation (circa 1987) was highly influential
and formed the basis of
-.Nm GNU tar .
+.Nm GNU tar
+(circa 1988).
Joerg Shilling's
.Nm star
archiver is another open-source (GPL) archiver (originally developed
circa 1985) which features complete support for pax interchange
format.
+.Pp
+This documentation was written as part of the
+.Nm libarchive
+and
+.Nm bsdtar
+project by
+.An Tim Kientzle Aq kientzle@FreeBSD.org .