HDF5 documents and links 
Introduction to HDF5 
HDF5 User Guide 
And in this document, the HDF5 Reference Manual  
H5   H5A   H5D   H5E   H5F   H5G   H5I   H5P  
H5R   H5S   H5T   H5Z   Tools   Datatypes  
(PDF of complete manual formatted as print volume)   

HDF5 Predefined Datatypes

The following datatypes are predefined in HDF5.

IEEE floating point datatypes

        H5T_IEEE_F32BE
        H5T_IEEE_F32LE
        H5T_IEEE_F64BE
        H5T_IEEE_F64LE

Standard datatypes

        H5T_STD_I8BE
        H5T_STD_I8LE
        H5T_STD_I16BE
        H5T_STD_I16LE
        H5T_STD_I32BE
        H5T_STD_I32LE
        H5T_STD_I64BE
        H5T_STD_I64LE
        H5T_STD_U8BE 
        H5T_STD_U8LE
        H5T_STD_U16BE
        H5T_STD_U16LE
        H5T_STD_U32BE
        H5T_STD_U32LE
        H5T_STD_U64BE 
        H5T_STD_U64LE
        H5T_STD_B8BE
        H5T_STD_B8LE
        H5T_STD_B16BE 
        H5T_STD_B16LE
        H5T_STD_B32BE
        H5T_STD_B32LE
        H5T_STD_B64BE 
        H5T_STD_B64LE
        H5T_STD_REF_OBJ
        H5T_STD_REF_DSETREG 

UNIX-specific datatypes

        H5T_UNIX_D32BE
        H5T_UNIX_D32LE
        H5T_UNIX_D64BE
        H5T_UNIX_D64LE

C-specific datatype

        H5T_C_S1

FORTRAN-specific datatype

        H5T_FORTRAN_S1

Intel-specific datatypes

        H5T_INTEL_I8
        H5T_INTEL_I16
        H5T_INTEL_I32
        H5T_INTEL_I64

        H5T_INTEL_U8
        H5T_INTEL_U16
        H5T_INTEL_U32
        H5T_INTEL_U64
        H5T_INTEL_B8
        H5T_INTEL_B16
        H5T_INTEL_B32
        H5T_INTEL_B64

        H5T_INTEL_F32
        H5T_INTEL_F64

DEC Alpha-specific datatypes

        H5T_ALPHA_I8
        H5T_ALPHA_I16
        H5T_ALPHA_I32
        H5T_ALPHA_I64

        H5T_ALPHA_U8
        H5T_ALPHA_U16
        H5T_ALPHA_U32
        H5T_ALPHA_U64
        H5T_ALPHA_B8
        H5T_ALPHA_B16
        H5T_ALPHA_B32
        H5T_ALPHA_B64

        H5T_ALPHA_F32
        H5T_ALPHA_F64

MIPS-specific datatypes

        H5T_MIPS_I8
        H5T_MIPS_I16
        H5T_MIPS_I32
        H5T_MIPS_I64

        H5T_MIPS_U8
        H5T_MIPS_U16
        H5T_MIPS_U32
        H5T_MIPS_U64
        H5T_MIPS_B8
        H5T_MIPS_B16
        H5T_MIPS_B32
        H5T_MIPS_B64

        H5T_MIPS_F32
        H5T_MIPS_F64

Predefined native datatypes

These are the datatypes detected by H5detect. Their names differ from other HDF5 datatype names as follows:
        H5T_NATIVE_CHAR
        H5T_NATIVE_SCHAR        
        H5T_NATIVE_UCHAR        

        H5T_NATIVE_SHORT        
        H5T_NATIVE_USHORT       

        H5T_NATIVE_INT          
        H5T_NATIVE_UINT         

        H5T_NATIVE_LONG         
        H5T_NATIVE_ULONG        
        H5T_NATIVE_LLONG        
        H5T_NATIVE_ULLONG       
        H5T_NATIVE_FLOAT        
        H5T_NATIVE_DOUBLE       
        H5T_NATIVE_LDOUBLE

        H5T_NATIVE_B8
        H5T_NATIVE_B16
        H5T_NATIVE_B32
        H5T_NATIVE_B64

        H5T_NATIVE_OPAQUE       
        H5T_NATIVE_HADDR
        H5T_NATIVE_HSIZE
        H5T_NATIVE_HSSIZE
        H5T_NATIVE_HERR
        H5T_NATIVE_HBOOL

ANSI C9x-specific native integer datatypes

        H5T_NATIVE_INT8
        H5T_NATIVE_UINT8
        H5T_NATIVE_INT_LEAST8
        H5T_NATIVE_UINT_LEAST8
        H5T_NATIVE_INT_FAST8 
        H5T_NATIVE_UINT_FAST8

        H5T_NATIVE_INT16
        H5T_NATIVE_UINT16
        H5T_NATIVE_INT_LEAST16
        H5T_NATIVE_UINT_LEAST16
        H5T_NATIVE_INT_FAST16
        H5T_NATIVE_UINT_FAST16
        H5T_NATIVE_INT32
        H5T_NATIVE_UINT32
        H5T_NATIVE_INT_LEAST32
        H5T_NATIVE_UINT_LEAST32
        H5T_NATIVE_INT_FAST32
        H5T_NATIVE_UINT_FAST32

        H5T_NATIVE_INT64
        H5T_NATIVE_UINT64
        H5T_NATIVE_INT_LEAST64
        H5T_NATIVE_UINT_LEAST64 
        H5T_NATIVE_INT_FAST64
        H5T_NATIVE_UINT_FAST64

FORTRAN90 API datatypes

        H5T_NATIVE_INTEGER
        H5T_NATIVE_REAL
        H5T_NATIVE_DOUBLE
        H5T_NATIVE_CHARACTER 
        H5T_STD_I8BE
        H5T_STD_I8LE
        H5T_STD_I16BE
        H5T_STD_I16LE
        H5T_STD_I32BE
        H5T_STD_I32LE
        H5T_STD_I64BE
        H5T_STD_I64LE
        H5T_STD_U8BE
        H5T_STD_U8LE
        H5T_STD_U16BE
        H5T_STD_U16LE
        H5T_STD_U32BE
        H5T_STD_U32LE
        H5T_STD_U64BE
        H5T_STD_U64LE
        H5T_IEEE_F32BE
        H5T_IEEE_F32LE
        H5T_IEEE_F64BE
        H5T_IEEE_F64LE
        H5T_STD_REF_OBJ
        H5T_STD_REF_DSETREG

HDF5 documents and links 
Introduction to HDF5 
HDF5 User Guide 
And in this document, the HDF5 Reference Manual  
H5   H5A   H5D   H5E   H5F   H5G   H5I   H5P  
H5R   H5S   H5T   H5Z   Tools   Datatypes  
(PDF of complete manual formatted as print volume)   

The HDF Group Help Desk:
Describes HDF5 Release 1.6.10, November 2009