diff --git a/include/pdp10-ar.h b/include/pdp10-ar.h
new file mode 100644
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--- /dev/null
+++ b/include/pdp10-ar.h
@@ -0,0 +1,109 @@
+/*
+ * pdp10-ar.h
+ *
+ * This is essentially the standard SVR4/GNU AR format, with 'char'
+ * replaced by 'pdp10_uint9_t' throughout.
+ * Groups of 4 bytes in the symbol table denote pdp10_uint36_t
+ * values rather than plain int or uint32_t values.
+ */
+#ifndef PDP10_AR_H
+#define PDP10_AR_H
+
+#include "pdp10-stdint.h"	/* pdp10_{u,}int{9,18,36}_t */
+
+#define PDP10_ARMAG	{ '!', '<', 'a', 'r', 'c', 'h', '>', '\n' }	/* String that begins an archive file.  */
+#define PDP10_SARMAG	8						/* Size of that string.  */
+
+#define PDP10_ARFMAG	{ '`', '\n' }					/* String in ar_fmag at end of each header.  */
+
+struct pdp10_ar_hdr {
+    pdp10_uint9_t ar_name[16];	/* Member file name, sometimes / terminated.  */
+    pdp10_uint9_t ar_date[12];	/* File date, decminal seconds since Epoch.  */
+    pdp10_uint9_t ar_uid[6];	/* User ID, in ASCII decimal.  */
+    pdp10_uint9_t ar_gid[6];	/* Group ID, in ASCII decimal.  */
+    pdp10_uint9_t ar_mode[8];	/* File mode, in ASCII octal.  */
+    pdp10_uint9_t ar_size[10];	/* File size, in ASCII decimal.  */
+    pdp10_uint9_t ar_fmag[2];	/* Always contains ARFMAG.  */
+};
+
+#define PDP10_ARHDR_SIZEOF	60
+
+/*
+ * Additional information summarized from the FreeBSD ar(5) manual page
+ * <http://howtounix.info/man/FreeBSD/man5/ar.5>.
+ *
+ * DESCRIPTION
+ *
+ * Th e archive file starts with an identifying byte sequence of the seven ASCII characters
+ * '!<arch>' followed by an ASCII linefeed character (see the constant "ARMAG" in the header
+ * file <ar.h>).
+ * Archive members follow the initial identifying byte sequence.  Each archive member is
+ * prefixed by a fixed size heade describing the file attributes associated with the member.
+ *
+ * Archive Headers
+ *
+ * Archive headers are placed at an even offset in the archive file.  If the data for an
+ * archive member ends at an odd byte offset, then a padding byte with value 0x0A is used
+ * to position the next archive header on an even byte offset.
+ *
+ * Unused bytes in the fields of an archive header are set to the value 0x20.
+ *
+ * Representing File Names
+ *
+ * SVR4/GNU
+ *	File names that are up to 15 characters long are stored directly in the ar_name
+ *	field of the header, terminated by a "/" character.
+ *	If the file name is larger than would fit in the space for the ar_name field,
+ *	then the actual file name is kept in the archive string table, and the decimal
+ *	offset of the file name in the string table is stored in the ar_name field,
+ *	prefixed by a "/" character.
+ *
+ * Special Archive Members
+ *
+ * The following archive members are special.
+ *
+ * "/"
+ *	In the SVR4/GNU variant of the archive format, the archive member with name "/"
+ *	denotes an archive symbol table.  If present, this member will be the very first
+ *	member of the archive.
+ *
+ * "//"
+ *	In the SVR4/GNU variant of the archive format, the archive member with name "//"
+ *	denotes the archive string table.  This special member is used to hold filenames
+ *	that do not fit in the file name field of the header.  If present, this member
+ *	immediately follows the archive symbol table if an archive symbol table is present,
+ *	or is the first member otherwise.
+ *
+ * Archive String Tables
+ *
+ * An archive string table is used in the SVR4/GNU archive format to hold file names that
+ * are too large to fit into the constraints of the ar_name field of the archive header.
+ * An archive string table contains a sequence of file names.  Each file name in the archive
+ * string table is terminated by the sequence 0x2F, 0x0A (the ARCII string "/\n").  No
+ * padding is used to separate adjacent file names.
+ *
+ * Archive Symbol Tables
+ *
+ * Archive symbol tables are used to speed up link editing by providing a mapping between
+ * the program symbols defined in the archive and the corresponding archive members.
+ * Archive symbol tables are managed by the ranlib utility.  The format of archive symbol
+ * tables is as follows:
+ *
+ * SVR4/GNU
+ *	In the SVR4/GNU archive format, the archive symbol table starts with a 4-byte binary
+ *	values consisting of the number of entries contained in the archive symbol table.
+ *	This could of entries is stored most significant byte first.  Next, there are 'count'
+ *	4-byte numbers, each stored most significant byte first.  Each number is a binary
+ *	offset to the archive header for the member in the archive file for the corresponding
+ *	symbol table entry.  After the binary offset values, there are 'count' NUL-terminated
+ *	strings in sequence, holding the symbol names for the corresponding symbol table entries.
+ */
+
+/*
+ * Further references:
+ * <https://blogs.oracle.com/ali/entry/64_bit_archives_needed>
+ * <http://linux.die.net/man/1/llvm-ar>
+ * "man -s 3HEAD ar.h" on Solaris 10
+ */
+
+#endif /* PDP10_AR_H */