Is the linear transfer function defined for values outside of [0, 1)?

According to ITU-T H.273 Table 3, what they call the "linear transfer function" is only defined for values within [0, 1). Does the Vulkan definition match this? The Khronos Data Format Specification makes me think that it does not:

a linear transfer function: for color data, there is a linear relationship between numerical pixel values and the intensity of additive colors

for this to be true always, the valid range must be all reals. Unless there is something else qualifying this which I am missing.

As an example, it seems like something on Linux (not super familiar with this part of the stack -- don't know if this is handled on my machine by Mesa or Gnome) assumes that the linear transfer function extends to values beyond [0, 1). If I present with COLOR_SPACE_BT709_LINEAR_EXT, I get different results (more significant than just quantization differences) based on whether my underlying format is FORMAT_A2B10G10R10_UNORM_PACK32 or FORMAT_R16G16B16A16_SFLOAT. I can make the two cases behave identical by clamping the values I write into the swapchain to [0, 1]. Thus it seems like the floating point format treats values greater than [0, 1) as meaningful.