Error in setting Joint axis element

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Hello,

I am trying to set a joint's axis according to its parent frame and I am using SDF 1.6, so according to the SDFFormat Specification I am using <use_parent_model_frame>1</use_parent_model_frame> in the axis element of my joint, but this is giving me the following error:

Warning [parser.cc:950] XML Element[use_parent_model_frame], child of element[joint] not defined in SDF. Ignoring[use_parent_model_frame]. You may have an incorrect SDF file, or an sdformat version that doesn't support this element.

But the model is opening just fine, but apparently the axis is not set correctly. So what's wrong? Thank you in advance.