arrowhead identification

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_minus">

<use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_plus"> <use xlink:href="/assets-global/icons/svg-sprite.svg?v=2020-07-15-215324-2a2b692-016223#ico_minus">