See how this goes...

@@ -21,0 +21,1 @@
+<s_inf>必用 can imply has to be used rather than is just needed</s_inf>

a note might be appropriate.  would be difficult to keep them separate as the glosses would end up being identical

I feel this is very subtle. Both Kojien and Daijrin give 必用 as a meaning for 必要 and vice versa. It could be split, with 必用 xrefed to 必要, or there could be a note saying 必用 implies something has to be used rather than is just needed, or we can leave it how it is.... Comments?

必用　－必ず用いるもの、必ず用いなくてはならないこと、動作主が能動的に使う
例：「指定の運動靴必用のこと」

必要　－必ず要るもの、なくてはならないこと
例：「眼鏡が必要になる」