The letters E — E in the root of the word (Cash / Cash, Hash / Hash, Tag / Tag, etc.)

Under the cut rule

1. The letter E is written after the prefix ending in a consonant (test, save) or the first part of a compound word (two-story, bromethyl) , as well as in complex words and abbreviations (political economy, power lines) . The letter E is written in the middle of the word after consonants, although it is pronounced [e]: manager, grotesque, specimen, orchid.

The exceptions are the words mayor, sir, peer, plein air, racketeering, as well as some proper names: Bela, Bacon, Ulan-Ude.

2. After the vowel and spell E : sharp, requiem, diet . The spelling of E after and is found only after prefixes on and (anti-aesthetic) , in complex foreign words, the first part of which ends in and (polyester) and in some proper names.
')
3. After the remaining vowels, the letter e is written : canoe, duet, poet, silhouette .
Exceptions: project, (projection, design), extravaganza, trajectory, registry , etc.

Source lingvotech.com

It turns out that it is necessary to write correctly like this: Cache, Tag, Slash, Flash, Hash, Krek, Brand, Stack, Pager, Track, Sleng.

Of course, you can also write them via E, but please no longer use two options at once.