Supported extensions

[hayohayo]

How can I get which extensions are supported? For example, glGetString(GL_EXTENSIONS) returns (sorted):
GL_EXT_multi_draw_arrays
GL_IMG_read_format
GL_IMG_texture_compression_pvrtc
GL_IMG_texture_format_BGRA8888
GL_OES_blend_equation_separate
GL_OES_blend_func_separate
GL_OES_blend_subtract
GL_OES_byte_coordinates
GL_OES_compressed_ETC1_RGB8_texture
GL_OES_compressed_paletted_texture
GL_OES_depth24
GL_OES_depth_texture
GL_OES_draw_texture
GL_OES_element_index_uint
GL_OES_extended_matrix_palette
GL_OES_fixed_point
GL_OES_fragment_precision_high
GL_OES_framebuffer_object
GL_OES_mapbuffer
GL_OES_matrix_get
GL_OES_matrix_palette
GL_OES_point_size_array
GL_OES_point_sprite
GL_OES_query_matrix
GL_OES_query_matrix
GL_OES_read_format
GL_OES_rgb8_rgba8
GL_OES_single_precision
GL_OES_stencil8
GL_OES_stencil_wrap
GL_OES_texture_cube_map
GL_OES_texture_env_crossbar
GL_OES_texture_float
GL_OES_texture_half_float
GL_OES_texture_mirrored_repeat
GL_OES_vertex_half_float

At the same time PVRVFrame prints to log that supported extensions are:
GL_EXT_multi_draw_arrays
GL_IMG_read_format
GL_IMG_texture_compression_pvrtc
GL_IMG_texture_format_BGRA8888
GL_OES_blend_equation_separate
GL_OES_blend_func_separate
GL_OES_blend_subtract
GL_OES_byte_coordinates
GL_OES_compressed_ETC1_RGB8_texture
GL_OES_compressed_paletted_texture
GL_OES_depth24
GL_OES_draw_texture
GL_OES_extended_matrix_palette
GL_OES_fixed_point
GL_OES_framebuffer_object
GL_OES_mapbuffer
GL_OES_matrix_get
GL_OES_matrix_palette
GL_OES_point_size_array
GL_OES_point_sprite
GL_OES_query_matrix
GL_OES_read_format
GL_OES_rgb8_rgba8
GL_OES_single_precision
GL_OES_stencil8
GL_OES_stencil_wrap
GL_OES_texture_cube_map
GL_OES_texture_env_crossbar
GL_OES_texture_mirrored_repeat

As you can see the lists are not exactly the same. In red is what is missing in the second list. I’m trying to use OES_vertex_half_float extension, because it’s said to be supported, but all my gl*Pointer() calls fail with INVALID_ENUM.

I created and “bound” a context for OpenGL ES 1.x. SDK I use is OGLES_WINDOWS_X86EMULATION_2.08.28.0634

Thanks