diff --git a/FORMATS.md b/FORMATS.md
index 50e88d97..31b74732 100644
--- a/FORMATS.md
+++ b/FORMATS.md
@@ -10,7 +10,10 @@
 
 | Archive Format         | Compression Format(s)                             | Compress/Decompress | Archive API     | Reader API | Writer API    |
 | ---------------------- | ------------------------------------------------- | ------------------- | --------------- | ---------- | ------------- |
-| Rar                    | Rar                                               | Decompress (1)      | RarArchive      | RarReader  | N/A           |
+| Ace                    | None                                              | Decompress          | N/A             | AceReader  | N/A           |
+| Arc                    | None, Packed, Squeezed, Crunched                  | Decompress          | N/A             | ArcReader  | N/A           |
+| Arj                    | None                                              | Decompress          | N/A             | ArjReader  | N/A           |
+| Rar                    | Rar                                               | Decompress          | RarArchive      | RarReader  | N/A           |
 | Zip (2)                | None, Shrink, Reduce, Implode, DEFLATE, Deflate64, BZip2, LZMA/LZMA2, PPMd                           | Both                | ZipArchive      | ZipReader  | ZipWriter     | 
 | Tar                    | None                                              | Both                | TarArchive      | TarReader  | TarWriter (3) |
 | Tar.GZip               | DEFLATE                                           | Both                | TarArchive      | TarReader  | TarWriter (3) |