C23A1 - MTWTFSS

Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday

C23A2 - Black Magic

AEIOU

C23A3 - Catch Rock If You Can

Find Rock by "Inspect" function in Google Chrome. (Right Click > Inspect)

C23A4 - Shakespeare Sort

William Shakespeare (bapt. 26 April 1564 – 23 April 1616) was an English playwright, poet and actor. He is regarded as the greatest writer in the English language and the world's pre-eminent dramatist.

C23A5 - Goodest English

By 谷歌剷屎你:
💩 Professor: Binary bits includes One and Zero.
🗿 Rock: What?
💩 Professor: For example, Ten is One, Zero, One, Zero.
🗿 Rock: What??
💩 Professor: Lets do an exercise now. Which of the followings has maximum number of bits One?
🗿 Rock: What???

C23A6 - Goodest Chinese

Search "FASCINATING COMPOSITIONS" on github and reach https://github.com/jonowo/FascinatingCompositions. Click on the link in the README to go to https://github.com/wykoj/compositions which contains fascinating compositions by STEM Team members.

C23A7 - 標題解碼

標題 is 中國香港九龍華仁書院電腦科主任李海峻老師精心調製之全校青少年信息學奧林匹克六月愚人節編程競賽。The words 信息、愚人、坎坷 etc are 雙聲, meaning they have the same 聲母. Take the 聲母 of each word in the 標題 to get a string.

C23A8 - Dark Reader

Invisible clues can be seen by installing the Dark Reader extension and apply dark theme to WYKOJ.
First clue can be found in C23A8: 6
Second clue can be found C23A4: 9
Third clue can be found in C23A1: times
Fourth clue can be found in C23A8, bold letters in the image: "fourth four"
Fifth clue can be found in C23A2: 2
Sixth clue can be found as morse code in C23A5: 0