I believe skills cards (particularly in the early sets) were created to implicitly require targeting a character with the skill as an active condition for playing the card.
This means that:
* you can't use your opponent's skill character to play your own card, which would otherwise be allowed;
* you can't change which skill character is referenced in the card's text between declaring the play of the card and it eventually resolving, which some might argue would otherwise be allowed;
* the removal from play of the targeted skill character (the one playing the card, according to the CRF) or the removal of that character's skill will prevent the resolution of the card, which some might argue could otherwise resolve.
This proposal (addition underlined) is to make the implicit rules explicit:
---CRF wrote:"(Foo) only" cards can only be played by characters with the (foo) skill. This means that satisfying the skill requirement of a card requires targeting a character with that skill.
Without this proposed clarification:
Some players have contested that Old Friendship and New Friendship can use your opponent's Diplomat to satisfy the "Diplomat only." requirement of the card. That is, according to the CRF, your card is being "played by" your opponent's character. Further, the CRF clarifications on these cards cannot be interpreted, since there is no "the diplomat" target. Another implication is that even though such cards are "played by"(existing CRF) certain characters when active conditions of the card are checked at play declaration, the cards can be "played by" entirely different characters when active conditions are checked at play resolution.
Similarly, you can use your opponent's Diplomat (anywhere) to satisfy Lordly Presence.
Similarly, Many Turns and Doublings can use your opponent's Ranger. See this alternative proposal to correct this particular situation by treating it as a one-off: https://councilofelrond.org/forum/viewt ... 145&t=3677
Similarly, Risky Blow can use the paired opponent's Warrior skill in CvCC to give presumably-anything-you-want (including your character) +3 to prowess and -1 to body against a strike.
[edits: added Lordly Presence example]