Minecraft – How to use CanPlaceOn or other tags to make a block placeable only on 1 block type

Try to give to the first gold block a name:

/give @p gold_block 1 0 {display:{Name:"a name"}}

And then run the /clear command like this:

/clear @p gold_block 0 1 {display:{Name:"a name"}}

This command will clear only the golden block that has the name "a name".

Now give your SPECIAL BLOCK, but with another name:

/give @p gold_block 1 0 {CanPlaceOn:[grass],display:{Name:"SPECIAL BLOCK"}}

You need to put another name that the clear command block doesn't affect.

Apparently, i was trying to use the wrong command, to do something the game doesn't allow. For what it's worth, i ended up using the /execute command to run data on dropped items. My thanks to Mr. Röling for his help.

Ex: execute as @e[type=item,scores={tool=3}] run data merge entity @s {Item:{tag:{CanDestroy:["coarse_dirt","gravel","sand","snow","snow_block"]}}}