We have a tag kakikaeji that is only applied to a single question - On the replacing of kanji made obsolete in the 1946 reforms with similar-looking kanji..
I am not sure what this tag is supposed to be for - it has no tag wiki; the only search results for "kakikaeji" (romanized) point back to this site; my IME refuses to give any conversions for かきかえじ that contain 字; and I cannot find any uses of 書き換え字, which is what I presume are the correct kanji for this term.