Data Validation for specific character set across named range

[Patchcord]

Hi, I'm having difficult defining this valid character set.

The valid characters are:
Numbers: ≤ 1
Letters: RDO
Special: : (The colon character only)

My name range: range1

Any asstance greatly appreciated!

 

[Patchcord]

Just updating the valid charcters:
The valid characters are:
Numbers: ≥ 0, ≤ 1
Letters: RDO
Special: : (The colon character only)

My named range: range1

 

[Cubist]

Try:

=AND(OR(ISNUMBER(A1)*(A1>=0)*(A1<=1),ISNUMBER(FIND(A1,"RDO:"))))

 

[Patchcord]

Try:

=AND(OR(ISNUMBER(A1)*(A1>=0)*(A1<=1),ISNUMBER(FIND(A1,"RDO:"))))

Thanks for helping me with this Cubist, much appreciated. Works well.