So i was making a map and i saw that when i made it so a diamond block could be placed on wool (which i could) it said that wool was missingno. But i still was able to place it on wool. So therefore this is a command error or a bug
PS here's the command for testing
/give @a minecraft:diamond_block 1 0 {CanPlaceOn:["minecraft:wool "],display:{Name:"The Missing Diamond Shard 1 out of 10"}}
Also a easy fix may be to make all block which have more then one form to have individual commands for example
If i wanted red wool i would type /give @p red_wool instead of /give @p wool 1 (data tag)
Many people may consider this a feature asking but this is a minor tweak in my perceptive
Though this will take more effort it will make variants of different blocks easier to access and a much better system than remembering numbers.
And this could be appplied to minecraft 1.12 because of the new blocks
Thank You for reading though it was quite long !