A holding device , comprising: - an accessory rail configured as an attachment interface for temporal attachment of equipment at a patient support ; and - a coupling comprising a first portion and a second portion , wherein the first portion of the coupling is configured to provide, in interaction with the second portion of the coupling, a movable connection for connecting the accessory rail to the patient support, wherein the accessory rail comprises a front side with the attachment interface configured as a rail profile being rigidly connected to the first portion of the coupling comprising a rear side with an accommodation, wherein the second portion of the coupling is a mounting device with a rail profile that is configured to be attached to the patient support, the mounting device being receivable within the accommodation so as to provide the movable connection; wherein the movable connection is configured to provide a horizontal sliding movement of the accessory rail with attached equipment in relation to the patient support, the accessory rail being movable to a parking position for the attached equipment when not used or required, the parking position being at least partly outside a range of the mounting rail to enlarge a movement range of the attached equipment. - an accessory rail configured as an attachment interface for temporal attachment of equipment at a patient support ; and - a coupling comprising a first portion and a second portion , wherein the first portion of the coupling is configured to provide, in interaction with the second portion of the coupling, a movable connection for connecting the accessory rail to the patient support, wherein the accessory rail comprises a front side with the attachment interface configured as a rail profile being rigidly connected to the first portion of the coupling comprising a rear side with an accommodation, wherein the second portion of the coupling is a mounting device with a rail profile that is configured to be attached to the patient support, the mounting device being receivable within the accommodation so as to provide the movable connection; wherein the movable connection is configured to provide a horizontal sliding movement of the accessory rail with attached equipment in relation to the patient support, the accessory rail being movable to a parking position for the attached equipment when not used or required, the parking position being at least partly outside a range of the mounting rail to enlarge a movement range of the attached equipment. wherein the accessory rail comprises a front side with the attachment interface configured as a rail profile being rigidly connected to the first portion of the coupling comprising a rear side with an accommodation, wherein the second portion of the coupling is a mounting device with a rail profile that is configured to be attached to the patient support, the mounting device being receivable within the accommodation so as to provide the movable connection; wherein the movable connection is configured to provide a horizontal sliding movement of the accessory rail with attached equipment in relation to the patient support, the accessory rail being movable to a parking position for the attached equipment when not used or required, the parking position being at least partly outside a range of the mounting rail to enlarge a movement range of the attached equipment. <EOS>