Invalid Data Value Cobblestone Wall

Invalid data value cobblestone walls are item forms of the cobblestone wall block with damage values outside of the usual range which cobblestone walls can usually be obtained in.

Obtaining
Without the use of commands, invalid data value cobblestone walls are unobtainable in the last versions in which they existed without inheriting them from a prior version in which they were obtainable.

Transmutation
Block transmutation with doors can be used to obtain cobblestone walls with metadata 4 and 5, and with arrows any metadata from 2 to 15 can be obtained. These blocks can be mined in 14w21b or earlier to obtain the item corresponding to these blocks.

For arrow transmutation, the initial block being transmutated must be a non-mossy cobblestone wall, i.e. a cobblestone wall block with metadata value 0. Mossy cobblestone walls cannot be transmutated. Any connections a cobblestone wall has to adjacent blocks are irrelevant, as these are not controlled by metadata.

Issues
Invalid data value cobblestone walls are an issue, and due to their removal, can be considered already fixed.