Global Phar bitmapped flags
Phar Signature format
What makes a phar a phar and not a tar or a zip?
PHP Manual

## Phar manifest file entry definition

Each file in the manifest contains the following information:

Phar Manifest file entry
Size in bytes | Description
--- | ---
4 bytes | Filename length in bytes
?? | Filename (length specified in previous)
4 bytes | Un-compressed file size in bytes
4 bytes | Unix timestamp of file
4 bytes | Compressed file size in bytes
4 bytes | CRC32 checksum of un-compressed file contents
4 bytes | Bit-mapped File-specific flags
4 bytes | Serialized File Meta-data length (0 for none)
?? | Serialized File Meta-data, stored in serialize() format

Note that as of API version 1.1.1, empty directories are stored as filenames with a trailing slash like my/directory/

The File-specific bitmap values recognized are:

Bitmap values recognized
Value | Description
--- | ---
0x000001FF | These bits are reserved for defining specific file permissions of a file. Permissions are used for fstat() and can be used to recreate desired permissions upon extraction.
0x00001000 | If set, this file is compressed with zlib compression
0x00002000 | If set, this file is compressed with bzip compression

Global Phar bitmapped flags
Phar Signature format
What makes a phar a phar and not a tar or a zip?
PHP Manual