⎕Ⓐ is a deprecated feature. Dyalog strongly recommends that you move away from the use of ⎕Ⓐ and of the underscored alphabet itself, as these symbols now constitute the sole remaining non-standard use of characters in Dyalog applications.
In Versions of Dyalog APL prior to Version 11.0, ⎕Ⓐ was a simple character vector, composed of the letters of the alphabet with underscores. If the Dyalog Alt font was in use, these symbols displayed as additional National Language characters.
⎕Ⓐ ⒶⒷⒸⒹⒺⒻⒼⒽⒾⒿⓀⓁⓂⓃⓄⓅⓆⓇⓈⓉⓊⓋⓌⓍⓎⓏ
For compatibility with previous versions of Dyalog APL, functions that contain references to ⎕Ⓐ will continue to return characters with the same index in ⎕AV as before. However, the display of ⎕Ⓐ is now ⎕Á, and the old underscored symbols appear as they did in previous Versions when the Dyalog Alt font was in use.
⎕Á ÁÂÃÇÈÊËÌÍÎÏÐÒÓÔÕÙÚÛÝþãìðòõ