Not Enunciating Hashem's Name as It Is Written
From Halachipedia
Saying Hashem's Name as It Is Written
Abaye Hava Mesader
- When recite Abaye Hava Omer a person should be careful to pause between the words Abaye and Hava since saying them quickly together sounds like the enunciation of Hashem's name as it is written. It is possible to skip the word Hava altogether.
http://halachayomit.co.il/en/default.aspx?HalachaID=2338
Saying the Letters
- Just as it is forbidden to recite Hashem's name as it is written, it is similarly forbidden to enunciate the letters of Hashem's name, Yud Hey Vav Hey.[1]
Regarding the Shem Yichud see Leshem_Yichud#Reciting_Hashem.27s_Name
Sources
- ↑ Yabia Omer OC 9:12