This page is a translation of GlyphWiki:関連字.
Furthermore, GlyphWiki uses the IPSJ-TS 0008 standard; the relationships between different characters.
So, when you search for the keyword “国” (kuni; “country”), you'd also get glyphs that specifies that kanji character such as “國”, “圀” or “囯” (the former 1969–1976 Singaporean simplified and variant form of 國) (see the next section for details).
The “Related character” field is a required input. Please specify the kanji itself or the code number such as “u4e00”. The related characters can be specified as URO (U+4E00…U+9FFF), Ext. A (U+3400…U+4DBF), Ext. B (U+20000…U+2A6DF), Ext. C (U+2A700…U+2B739), Ext. D (U+2B740…U+2B81D), Ext. E (U+2B820…U+2CEA1), Ext. F (U+2CEB0…U+2EBE0), Ext. G (U+30000…U+3134A), Ext. H (U+31350…U+323AF) and some 12 characters of CJK Compatibility Ideographs (U+F900…U+FAFF). These characters are the same as those specified in CJK Unified Ideographs in Unicode 13.0.